Endmyopia Wiki - User contributions [en]

Lens Complexity

2021-04-22T19:27:48Z

Deadpan:

A simple pair of glasses has spherical lenses of similar power. If one eye is weaker than the other, or you have [[astigmatism]], lenses to compensate for that are more complex. EM recommends<ref name="EndMyopia Blog: How To Reduce Prescription Complexity">{{Cite web |title=Pro Topic: How To Reduce Prescription Complexity - Endmyopia |url=https://endmyopia.org/pro-topic-how-to-reduce-prescription-complexity/ |website=endmyopia.org |access-date=2020-06-05}}</ref><ref name="EndMyopia Blog: Reducing Potential Harmful Prescription Complexity">{{Cite web |title=Reducing Potential Harmful Prescription Complexity |url=https://endmyopia.org/eyesight-health-reducing-potential-harmful-prescription-complexity/ |website=endmyopia.org |access-date=2020-06-05}}</ref> that you start with small and even [[spherical reductions]] first, then after you've accomplished a few of those, then work on reducing complexity.

[[Guide:Reducing lens complexity]]
==References==
{{reflist}}

[[Category:Articles]]

NITM

2020-06-21T05:20:50Z

Deadpan: Redirected page to Pseudomyopia

#REDIRECT [[Pseudomyopia]]

Guide:Resolving double vision

2020-06-17T05:47:48Z

Deadpan: /* What's happening */ EndMyopia:Optometry degrees optional

{{Under_construction}}

[[File:double-vision-blur.png|right|600px]]

Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].

==What's happening==
The eyes are designed to optimize vision, adapting based on environmental feedback.{{citation needed}} This is a normal thing that the eyes do from early childhood.{{citation needed}} The eyeball changes shape and size to optimize the [[focal plane]] while the [[visual cortex]] interprets the signal.{{citation needed}} Returning from [[lens-induced myopia]] involves a drastic change to the [[focal plane]], even when it is carried out over a long period of time; the change is larger than anything the [[visual cortex]] would have encountered in nature, without lenses.

The change to the size and shape of the eyeball, in response to [[blur]], happens relatively quickly. The [[double vision]] is a lag-period where the [[visual cortex]] is learning to interpret the changed signal it is receiving; it is learning to "align" the images.

Because the changes to the eye and the brain don't occur at the same pace progression of visual perception is generally experienced as:

'''Blur > Double Vision > Clarity'''

Sometimes [[double vision]] is difficult to resolve and the visual perception may cycle between [[double vision]] and clarity a few times over weeks or months before coming to rest at clarity, especially at [[lower diopters]].

TODO: Add reference to https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

==Fusing the images==

==When to reduce?==

==References==
{{reflist}}

==See also==

[[Category:Guides]]

Focal plane

2020-06-17T05:39:20Z

Deadpan: Redirected page to Focal length

#REDIRECT [[focal length]]

Guide:Resolving double vision

2020-06-17T05:38:40Z

Deadpan:

{{Under_construction}}

[[File:double-vision-blur.png|right|600px]]

Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].

==What's happening==
The eyes are designed to optimize vision, adapting based on environmental feedback.{{citation needed}} This is a normal thing that the eyes do from early childhood.{{citation needed}} The eyeball changes shape and size to optimize the [[focal plane]] while the [[visual cortex]] interprets the signal.{{citation needed}} Returning from [[lens-induced myopia]] involves a drastic change to the [[focal plane]], even when it is carried out over a long period of time; the change is larger than anything the [[visual cortex]] would have encountered in nature, without lenses.

The change to the size and shape of the eyeball, in response to [[myopic defocus]], happens relatively quickly. The [[double vision]] is a lag-period where the [[visual cortex]] is learning to interpret the changed signal it is receiving; it is learning to "align" the images.

Because the changes to the eye and the brain don't occur at the same pace progression of visual perception is generally experienced as:

'''Blur > Double Vision > Clarity'''

Sometimes [[double vision]] is difficult to resolve and the visual perception may cycle between [[double vision]] and clarity a few times over weeks or months before coming to rest at clarity, especially at [[lower diopters]].

TODO: Add reference to https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

==Fusing the images==

==When to reduce?==

==References==
{{reflist}}

==See also==

[[Category:Guides]]

Hyperopic defocus

2020-06-17T05:34:58Z

Deadpan:

{{Under_construction}}
'''Hyperopic defocus''' the technical term used by research papers to describe the [[blur#Myopic_vs_Hyperopic_Blur|blur]] caused by having the image focused behind the retina. It would normally be resolved automatically by [[accommodation]], but for [[hyperopia]] (far-sightedness), the lens is not strong enough to do (for near objects).

Studies show that it is a stimulus which, over time, can cause [[axial elongation]].

==See also==
[[Myopic defocus]]

==References==
{{reflist}}

Guide:Resolving double vision

2020-06-17T05:33:35Z

Deadpan: /* What's happening */ error correction: hyperopic defocus -> myopic defocus

{{Under_construction}}

[[File:double-vision-blur.png|right|600px]]

Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].

==What's happening==
The eyes are designed to optimize vision, adapting based on environmental feedback.{{citation needed}} This is a normal thing that the eyes do from early childhood.{{citation needed}} The eyeball changes shape and size to optimize the [[focal plane]] while the [[visual cortex]] interprets the signal.{{citation needed}} Returning from [[lens induced myopia]] involves a drastic change to the [[focal plane]], even when it is carried out over a long period of time; the change is larger than anything the [[visual cortex]] would have encountered in nature, without lenses.

The change to the size and shape of the eyeball, in response to [[myopic defocus]], happens relatively quickly. The [[double vision]] is a lag-period where the [[visual cortex]] is learning to interpret the changed signal it is receiving; it is learning to "align" the images.

Because the changes to the eye and the brain don't occur at the same pace progression of visual perception is generally experienced as:

'''Blur > Double Vision > Clarity'''

Sometimes [[double vision]] is difficult to resolve and the visual perception may cycle between [[double vision]] and clarity a few times over weeks or months before coming to rest at clarity, especially at [[lower diopters]].

TODO: Add reference to https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

==Fusing the images==

==When to reduce?==

==References==
{{reflist}}

==See also==

[[Category:Guides]]

Guide:Resolving double vision

2020-06-17T05:27:49Z

Deadpan: /* What's happening */ Added a basic explanation, needs expansion and citations.

{{Under_construction}}

[[File:double-vision-blur.png|right|600px]]

Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].

==What's happening==
The eyes are designed to optimize vision, adapting based on environmental feedback.{{citation needed}} This is a normal thing that the eyes do from early childhood.{{citation needed}} The eyeball changes shape and size to optimize the [[focal plane]] while the [[visual cortex]] interprets the signal.{{citation needed}} Returning from [[lens induced myopia]] involves a drastic change to the [[focal plane]], even when it is carried out over a long period of time; the change is larger than anything the [[visual cortex]] would have encountered in nature, without lenses.

The change to the size and shape of the eyeball, in response to [[hyperopic defocus]], happens relatively quickly. The [[double vision]] is a lag-period where the [[visual cortex]] is learning to interpret the changed signal it is receiving; it is learning to "align" the images.

Because the changes to the eye and the brain don't occur at the same pace progression of visual perception is generally experienced as:

'''Blur > Double Vision > Clarity'''

Sometimes [[double vision]] is difficult to resolve and the visual perception may cycle between [[double vision]] and clarity a few times over weeks or months before coming to rest at clarity, especially at [[lower diopters]].

TODO: Add reference to https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

==Fusing the images==

==When to reduce?==

==References==
{{reflist}}

==See also==

[[Category:Guides]]

Guide:Resolving double vision

2020-06-17T05:03:22Z

Deadpan: Added an (edited) image from the blog comparing double vision and blur.

Guide:The Last Diopter

2020-06-17T04:56:01Z

Deadpan: Shrank the gif a little

{{Under_construction}}
[[File:Milhouse-now-girls.gif|right|400px]]
The last diopter: it's a grind.
Hopefully you've already [[Guide:Reducing lens complexity|equalized your lenses]].
{{clear}}
==Transitioning to no glasses==
Begin modulating your walks with some time spent wearing 20/20 crystal clear correction and some time spent with no correction while practicing [[active focus]] and [[Guide:Resolving double vision|double vision resolve]].

As the months pass, spend more of the time without lenses and less of the time with lenses.

==When are glasses no longer needed==

One day, you'll put your glasses back on and not see any improvement in clarity. You're done with normalized lenses. (TODO: cite an EM source for this)

==Final Stretch: Improvement without any lenses==
TODO: talk about how to improve, now that you have no lenses to crutch on.

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

File:Double-vision-blur.png

2020-06-17T04:52:03Z

Deadpan: Source: https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

== Summary ==
Source: https://endmyopia.org/pro-topic-double-vision-ruining-your-life/
== Licensing ==
{{jake-copyright}}

Guide:Resolving double vision

2020-06-17T04:43:03Z

Deadpan: /* When is it safe to lower the prescription? */ Not a "prescription"

{{Under_construction}}
Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].
==What's happening==

Blur > Double Vision > Clarity

TODO: Add reference to https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

==Fusing the images==

==When to reduce?==

==References==
{{reflist}}

==See also==

[[Category:Guides]]

Guide:Reducing lens complexity

2020-06-17T04:40:55Z

Deadpan: /* How to reduce lens complexity */ Formatted example explanations as sentences.

{{Under_construction}}

TODO: this article needs to be expanded for edge cases like already low diopters.

==When to reduce lens complexity==

[[Lens complexity]] is best reduced before getting into the [[low diopters]] range. Ideally, both eyes would be equal before the normalized correction reaches -1.5 [[diopters]].{{citation needed}}

==How to reduce lens complexity==

'''Make your first reduction a simple [[spherical]] reduction. This will teach you the basics of the [[EndMyopia]] methods.'''

There are two types of reductions:

* <div>A simple reduction is a 0.25 [[diopter]] drop in lense power for both eyes, simultaneously</div>
* <div>An equalizing reduction is a 0.25 [[diopter]] drop in lense power for one eye, the eye with greater correction (more negative)</div>

An equalizing reduction is done to bring the eyes closer to having the same level of correction.

Either type of reduction can be applied to [[spherical]] power or [[cylindrical]] power.

'''There are four rules for reducing complexity:'''
# <div>Alternate types of reductions. Simple > Equalizing > Simple > Equalizing...</div>
# <div>Change only spherical or only cylindrical and never both simultaneously.</div>
# <div>For an equalizing reduction, change both differential lenses and normalized lenses simultaneously to keep the [[focal planes]] in sync.</div>
# <div>For a simple reduction, change differential lenses a few weeks after normalized lenses to keep changes to [[focal planes]] to a minimum.</div>

'''A note on rule 3 and rule 4:''' Keeping focal planes in sync is a higher priority than keeping changes to focal planes to a minimum, thus rule 3 exists.

{| class="wikitable" style="text-align:center;"
|+ Example Spherical Reduction Schedule
|-
! style="text-align:left;" | Reduction Type
! colspan="2" | Normalized
! colspan="2" | Differentials
! style="text-align:left;" | Explanation
|-
| style="text-align:left;" |
| Left
| Right
| Left
| Right
| style="text-align:left;" |
|-
| rowspan="2" style="text-align:left;" |
| -3.50
| -4.00
| -2.25
| -2.75
| style="text-align:left;" | This is the '''starting point'''.
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|-
| rowspan="4" | Simple
| -3.25
| -3.75
|
|
| style="text-align:left;" | Perform normalized reduction.
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| (rule 4)
|-
|
|
| -2.00
| -2.50
| style="text-align:left;" | Perform differential reduction.
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| rowspan="2" | Equalizing
| -3.25
| -3.50
| -2.00
| -2.25
| style="text-align:left;" | Both norms and diffs are reduced simultaneously. (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks
|
|-
| rowspan="4" | Simple
| -3.00
| -3.25
|
|
| style="text-align:left;" | Perform normalized reduction.
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| (rule 4)
|-
|
|
| -1.75
| -2.00
| style="text-align:left;" | Perform differential reduction.
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| rowspan="2" | Equalizing
| -3.00
| -3.00
| -1.75
| -1.75
| style="text-align:left;" | Both norms and diffs are reduced simultaneously. (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks
|
|}

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:Reducing lens complexity

2020-06-16T20:34:51Z

Deadpan: /* When to reduce lens complexity */

{{Under_construction}}

TODO: this article needs to be expanded for edge cases like already low diopters.

==When to reduce lens complexity==

[[Lens complexity]] is best reduced before getting into the [[low diopters]] range. Ideally, both eyes would be equal before the normalized correction reaches -1.5 [[diopters]]. (TODO: cite an EM source for this)

==How to reduce lens complexity==

'''Make your first reduction a simple [[spherical]] reduction. This will teach you the basics of the [[EndMyopia]] methods.'''

There are two types of reductions:

* <div>A simple reduction is a 0.25 [[diopter]] drop in lense power for both eyes, simultaneously</div>
* <div>An equalizing reduction is a 0.25 [[diopter]] drop in lense power for one eye, the eye with greater correction (more negative)</div>

An equalizing reduction is done to bring the eyes closer to having the same level of correction.

Either type of reduction can be applied to [[spherical]] power or [[cylindrical]] power.

'''There are four rules for reducing complexity:'''
# <div>Alternate types of reductions. Simple > Equalizing > Simple > Equalizing...</div>
# <div>Change only spherical or only cylindrical and never both simultaneously.</div>
# <div>For an equalizing reduction, change both differential lenses and normalized lenses simultaneously to keep the [[focal planes]] in sync.</div>
# <div>For a simple reduction, change differential lenses a few weeks after normalized lenses to keep changes to [[focal planes]] to a minimum.</div>

'''A note on rule 3 and rule 4:''' Keeping focal planes in sync is a higher priority than keeping changes to focal planes to a minimum, thus rule 3 exists.

{| class="wikitable" style="text-align:center;"
|+ Example Spherical Reduction Schedule
|-
! style="text-align:left;" | Reduction Type
! colspan="2" | Normalized
! colspan="2" | Differentials
! style="text-align:left;" | Explanation
|-
| style="text-align:left;" |
| Left
| Right
| Left
| Right
| style="text-align:left;" |
|-
| rowspan="2" style="text-align:left;" |
| -3.50
| -4.00
| -2.25
| -2.75
| style="text-align:left;" | Starting point
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|-
| rowspan="4" | Simple
| -3.25
| -3.75
|
|
| style="text-align:left;" | perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| (rule 4)
|-
|
|
| -2.00
| -2.50
| style="text-align:left;" | perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| rowspan="2" | Equalizing
| -3.25
| -3.50
| -2.00
| -2.25
| style="text-align:left;" | both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks
|
|-
| rowspan="4" | Simple
| -3.00
| -3.25
|
|
| style="text-align:left;" | perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| (rule 4)
|-
|
|
| -1.75
| -2.00
| style="text-align:left;" | perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| rowspan="2" | Equalizing
| -3.00
| -3.00
| -1.75
| -1.75
| style="text-align:left;" | both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks
|
|}

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:Reducing lens complexity

2020-06-16T17:12:22Z

Deadpan: /* How to reduce lens complexity */ Added a reduction type column to the example table.

{{Under_construction}}

TODO: this article needs to be expanded for edge cases like already low diopters.

==When to reduce lens complexity==

[[Lens complexity]] is best reduced before getting into the [[low diopters]] range. Ideally, both eyes would be equal before -1.5 [[diopters]]. (TODO: cite an EM source for this)

==How to reduce lens complexity==

'''Make your first reduction a simple [[spherical]] reduction. This will teach you the basics of the [[EndMyopia]] methods.'''

There are two types of reductions:

* <div>A simple reduction is a 0.25 [[diopter]] drop in lense power for both eyes, simultaneously</div>
* <div>An equalizing reduction is a 0.25 [[diopter]] drop in lense power for one eye, the eye with greater correction (more negative)</div>

An equalizing reduction is done to bring the eyes closer to having the same level of correction.

Either type of reduction can be applied to [[spherical]] power or [[cylindrical]] power.

'''There are four rules for reducing complexity:'''
# <div>Alternate types of reductions. Simple > Equalizing > Simple > Equalizing...</div>
# <div>Change only spherical or only cylindrical and never both simultaneously.</div>
# <div>For an equalizing reduction, change both differential lenses and normalized lenses simultaneously to keep the [[focal planes]] in sync.</div>
# <div>For a simple reduction, change differential lenses a few weeks after normalized lenses to keep changes to [[focal planes]] to a minimum.</div>

'''A note on rule 3 and rule 4:''' Keeping focal planes in sync is a higher priority than keeping changes to focal planes to a minimum, thus rule 3 exists.

{| class="wikitable" style="text-align:center;"
|+ Example Spherical Reduction Schedule
|-
! style="text-align:left;" | Reduction Type
! colspan="2" | Normalized
! colspan="2" | Differentials
! style="text-align:left;" | Explanation
|-
| style="text-align:left;" |
| Left
| Right
| Left
| Right
| style="text-align:left;" |
|-
| rowspan="2" style="text-align:left;" |
| -3.50
| -4.00
| -2.25
| -2.75
| style="text-align:left;" | Starting point
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|-
| rowspan="4" | Simple
| -3.25
| -3.75
|
|
| style="text-align:left;" | perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| (rule 4)
|-
|
|
| -2.00
| -2.50
| style="text-align:left;" | perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| rowspan="2" | Equalizing
| -3.25
| -3.50
| -2.00
| -2.25
| style="text-align:left;" | both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks
|
|-
| rowspan="4" | Simple
| -3.00
| -3.25
|
|
| style="text-align:left;" | perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| (rule 4)
|-
|
|
| -1.75
| -2.00
| style="text-align:left;" | perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| rowspan="2" | Equalizing
| -3.00
| -3.00
| -1.75
| -1.75
| style="text-align:left;" | both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center; font-weight:bold;" | wait 8 - 16 weeks
|
|}

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:Reducing lens complexity

2020-06-16T17:05:25Z

Deadpan: /* How to reduce lens complexity */

{{Under_construction}}

TODO: this article needs to be expanded for edge cases like already low diopters.

==When to reduce lens complexity==

[[Lens complexity]] is best reduced before getting into the [[low diopters]] range. Ideally, both eyes would be equal before -1.5 [[diopters]]. (TODO: cite an EM source for this)

==How to reduce lens complexity==

'''Make your first reduction a simple [[spherical]] reduction. This will teach you the basics of the [[EndMyopia]] methods.'''

There are two types of reductions:

* <div>A simple reduction is a 0.25 [[diopter]] drop in lense power for both eyes, simultaneously</div>
* <div>An equalizing reduction is a 0.25 [[diopter]] drop in lense power for one eye, the eye with greater correction (more negative)</div>

An equalizing reduction is done to bring the eyes closer to having the same level of correction.

Either type of reduction can be applied to [[spherical]] power or [[cylindrical]] power.

'''There are four rules for reducing complexity:'''
# <div>Alternate types of reductions. Simple > Equalizing > Simple > Equalizing...</div>
# <div>Change only spherical or only cylindrical and never both simultaneously.</div>
# <div>For an equalizing reduction, change both differential lenses and normalized lenses simultaneously to keep the [[focal planes]] in sync.</div>
# <div>For a simple reduction, change differential lenses a few weeks after normalized lenses to keep changes to [[focal planes]] to a minimum.</div>

'''A note on rule 3 and rule 4:''' Keeping focal planes in sync is a higher priority than keeping changes to focal planes to a minimum, thus rule 3 exists.

{| class="wikitable" style="text-align:center;"
|+ Example Spherical Reduction Schedule
|-
! colspan="2" | Normalized
! colspan="2" | Differentials
! style="text-align:left;" | Explanation
|-
| Left
| Right
| Left
| Right
| style="text-align:left;" |
|-
| -3.50
| -4.00
| -2.25
| -2.75
| style="text-align:left;" | Starting point
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|-
| -3.25
| -3.75
|
|
| style="text-align:left;" | Simple: perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| rule 4
|-
|
|
| -2.00
| -2.50
| style="text-align:left;" | Simple: perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| -3.25
| -3.50
| -2.00
| -2.25
| style="text-align:left;" | Equalizing: both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|-
| -3.00
| -3.25
|
|
| style="text-align:left;" | Simple: perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| rule 4
|-
|
|
| -1.75
| -2.00
| style="text-align:left;" | Simple: perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| -3.00
| -3.00
| -1.75
| -1.75
| style="text-align:left;" | Equalizing: both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|}

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:Reducing lens complexity

2020-06-16T17:04:46Z

Deadpan: /* How to reduce lens complexity */ Changed the example to a table.

{{Under_construction}}

TODO: this article needs to be expanded for edge cases like already low diopters.

==When to reduce lens complexity==

[[Lens complexity]] is best reduced before getting into the [[low diopters]] range. Ideally, both eyes would be equal before -1.5 [[diopters]]. (TODO: cite an EM source for this)

==How to reduce lens complexity==

'''Make your first reduction a simple [[spherical]] reduction. This will teach you the basics of the [[EndMyopia]] methods.'''

There are two types of reductions:

* <div>A simple reduction is a 0.25 [[diopter]] drop in lense power for both eyes, simultaneously</div>
* <div>An equalizing reduction is a 0.25 [[diopter]] drop in lense power for one eye, the eye with greater correction (more negative)</div>

An equalizing reduction is done to bring the eyes closer to having the same level of correction.

Either type of reduction can be applied to [[spherical]] power or [[cylindrical]] power.

'''There are four rules for reducing complexity:'''
# <div>Alternate types of reductions. Simple > Equalizing > Simple > Equalizing...</div>
# <div>Change only spherical or only cylindrical and never both simultaneously.</div>
# <div>For an equalizing reduction, change both differential lenses and normalized lenses simultaneously to keep the [[focal planes]] in sync.</div>
# <div>For a simple reduction, change differential lenses a few weeks after normalized lenses to keep changes to [[focal planes]] to a minimum.</div>

'''A note on rule 3 and rule 4:''' Keeping focal planes in sync is a higher priority than keeping changes to focal planes to a minimum, thus rule 3 exists.

{| class="wikitable" style="text-align:center;"
|+ Example Spherical Reduction Schedule
|-
! colspan="2" | Normalized
! colspan="2" | Differentials
! style="text-align:left;" | Explanation
|-
| Left
| Right
| Left
| Right
| style="text-align:left;" |
|-
| -3.50
| -4.00
| -2.25
| -2.75
| style="text-align:left;" | Starting point
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|-
| -3.25
| -3.75
|
|
| style="text-align:left;" | Simple: perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| rule 4
|-
|
|
| -2.00
| -2.50
| style="text-align:left;" | Simple: perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| -3.25
| -3.50
| -2.00
| -2.25
| style="text-align:left;" | Equalizing: both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|-
| -3.00
| -3.25
|
|
| style="text-align:left;" | Simple: perform normalized reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
| rule 4
|-
|
|
| -1.75
| -2.00
| style="text-align:left;" | Simple: perform differential reduction
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 4 - 8 weeks
|
|- style="font-weight:bold;"
| -3.00
| -3.00
| -1.75
| -1.75
| style="text-align:left;" | Equalizing: both norms and diffs are reduced simultaneously (rule 3)
|- style="text-align:left;"
| colspan="4" style="text-align:center;" | wait 8 - 16 weeks
|
|}

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide talk:Reducing lens complexity

2020-06-15T22:29:23Z

Deadpan: /* Reduction Example */

==Reduction Example==
{{re|Iceghoul}}I modified your example because it didn't look quite right to me. The differentials weren't consistently 1.25 diopters lower than the normalized and that's why I changed it but if you intended what you had then change it back! Maybe we should use a table to organize the layout...perhaps that will help clarify the example? | [[User:Deadpan|Deadpan]] ([[User talk:Deadpan|talk]]) 22:28, 15 June 2020 (UTC)

Guide talk:Reducing lens complexity

2020-06-15T22:28:24Z

Deadpan: /* Reduction Example */

==Reduction Example==

@Iceghoul I modified your example because it didn't look quite right to me. The differentials weren't consistently 1.25 diopters lower than the normalized and that's why I changed it but if you intended what you had then change it back! Maybe we should use a table to organize the layout...perhaps that will help clarify the example? | [[User:Deadpan|Deadpan]] ([[User talk:Deadpan|talk]]) 22:28, 15 June 2020 (UTC)

Guide talk:Reducing lens complexity

2020-06-15T22:28:13Z

Deadpan: Created page with "==Reduction Example== @Iceghoul I modified your example because it didn't look quite right to me. The differentials weren't consistently 1.25 diopters lower than the normaliz..."

==Reduction Example==

@Iceghoul I modified your example because it didn't look quite right to me. The differentials weren't consistently 1.25 diopters lower than the normalized and that's why I changed it but if you intended what you had then change it back! Maybe we should use a table to organize the layout...perhaps that will help clarify the example? [[User:Deadpan|Deadpan]] ([[User talk:Deadpan|talk]]) 22:28, 15 June 2020 (UTC)

Guide:Reducing lens complexity

2020-06-15T22:25:30Z

Deadpan: Left Eye/Right Eye differentials were swapped (I think)

Guide:The Last Diopter

2020-06-15T16:18:02Z

Deadpan: /* Transitioning to no glasses */ Removed some stray text

{{Under_construction}}
[[File:Milhouse-now-girls.gif|right]]
The last diopter: it's a grind.
Hopefully you've already [[Guide:Reducing lens complexity|equalized your lenses]].
{{clear}}
==Transitioning to no glasses==
Begin modulating your walks with some time spent wearing 20/20 crystal clear correction and some time spent with no correction while practicing [[active focus]] and [[Guide:Resolving double vision|double vision resolve]].

As the months pass, spend more of the time without lenses and less of the time with lenses.

==When are glasses no longer needed==

One day, you'll put your glasses back on and not see any improvement in clarity. You're done with normalized lenses. (TODO: cite an EM source for this)

==Final Stretch: Improvement without any lenses==
TODO: talk about how to improve, now that you have no lenses to crutch on.

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Focal planes

2020-06-15T16:13:15Z

Deadpan: Redirected page to Focal length

#REDIRECT [[Focal length]]

Guide:Reducing lens complexity

2020-06-15T16:13:03Z

Deadpan:

Guide:Reducing lens complexity

2020-06-15T16:11:31Z

Deadpan: Added the *basics*, needs expansion for sure

Cylindrical

2020-06-15T16:03:23Z

Deadpan: Redirected page to Cylinder

#REDIRECT [[Cylinder]]

Low diopters

2020-06-15T16:01:58Z

Deadpan: Redirected page to Myopia#Low Myopia

#REDIRECT [[Myopia#Low_Myopia]]

Guide:The Last Diopter

2020-06-15T15:58:13Z

Deadpan: Trying to merge the changes ¯\_(ツ)_/¯

{{Under_construction}}
[[File:Milhouse-now-girls.gif|right]]
The last diopter: it's a grind.
Hopefully you've already [[Guide:Reducing lens complexity|equalized your lenses]].
{{clear}}
==Transitioning to no glasses==
Begin modulating your walks with some time spent wearing 20/20 crystal clear correction and some time spent with no correction while practicing [[active focus]] and [[Guide:Resolving double vision|double vision resolve]].

As the months pass, spend more of the time without lenses and less of the time with lenses.==Transitioning to no glasses==

==When are glasses no longer needed==

One day, you'll put your glasses back on and not see any improvement in clarity. You're done with normalized lenses. (TODO: cite an EM source for this)

==Final Stretch: Improvement without any lenses==
TODO: talk about how to improve, now that you have no lenses to crutch on.

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:The Last Diopter

2020-06-15T15:56:58Z

Deadpan:

{{Under_construction}}
[[File:Milhouse-now-girls.gif|right]]
The last diopter: it's a grind.
Hopefully you've already [[Guide:Reducing lens complexity|equalized your lenses]].
{{clear}}
==How to transition to wearing no glasses for distance==
Begin modulating your walks with some time spent wearing 20/20 crystal clear correction and some time spent with no correction while practicing [[active focus]] and [[Guide:Resolving double vision|double vision resolve]].

As the months pass, spend more of the time without lenses and less of the time with lenses.==Transitioning to no glasses==

==When are glasses no longer needed==

One day, you'll put your glasses back on and not see any improvement in clarity. You're done with normalized lenses. (TODO: cite an EM source for this)

==Final Stretch: Improvement without any lenses==
TODO: talk about how to improve, now that you have no lenses to crutch on.

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:Reducing lens complexity

2020-06-15T15:51:31Z

Deadpan: Created page with "{{Under_construction}} TODO: this article needs to be expanded for edge cases like already low diopters. ==When to reduce lens complexity== Lens complexity is best redu..."

Guide:The Last Diopter

2020-06-15T15:31:36Z

Deadpan:

{{Under_construction}}
[[File:Milhouse-now-girls.gif|right]]
(pro topic) It's a grind.
==How to transition to wearing no glasses for distance==

==When are glasses no longer needed==

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

File:Milhouse-now-girls.gif

2020-06-15T15:30:05Z

Deadpan: NOW YOU'LL GET THE GIRLS YOU SEEK

== Summary ==
NOW YOU'LL GET THE GIRLS YOU SEEK
== Licensing ==
{{meme-copyright}}

Guide:The Last Diopter

2020-06-15T05:57:38Z

Deadpan: Created page with "{{Under_construction}} (pro topic) It's a grind. ==How to transition to wearing no glasses for distance== ==When are glasses no longer needed== ==References== {{reflist}}..."

{{Under_construction}}

(pro topic) It's a grind.
==How to transition to wearing no glasses for distance==

==When are glasses no longer needed==

==References==
{{reflist}}

==See also==

[[Guide:Resolving double vision]]

[[Category:Guides]]

Guide:Resolving double vision

2020-06-15T05:48:10Z

Deadpan:

{{Under_construction}}
Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].
==What's happening==

Blur > Double Vision > Clarity

TODO: Add reference to https://endmyopia.org/pro-topic-double-vision-ruining-your-life/

==Fusing the images==

==When is it safe to lower the prescription?==

==References==
{{reflist}}

==See also==

[[Category:Guides]]

Help:How to contribute

2020-06-14T20:37:33Z

Deadpan: /* Writing maths */ Gave a small sample of what's possible with formatting.

{{EM help}}
[[File:Kermit the frog typing.gif|right]]
<center>'''Looking for [[EndMyopia:Policies|wiki policies]]?'''</center>
'''If it ain't broke, don't fix it'''. That is the guiding principle behind this help article ;)

The wiki runs on [https://www.mediawiki.org/wiki/MediaWiki MediaWiki], the same wiki software that powers Wikipedia and probably every other wiki you've come across on the internet. As a result, '''countless other people have written guides far better than we could ever hope to write about how to contribute to the wiki'''. So, no point in reinventing the wheel with this one.

Please try to keep in mind the specifics of how contribution will work here. None of the policies of Wikipedia or any other wiki applies here, we have our own policy articles. We are [[EM:Biased point of view|not written from a neutral point of view]], referencing guidelines are fairly relaxed and humour is encouraged in articles wherever possible for entertainment value to the reader. But as for syntax and the technicalities of editing, you can't get much better than what's already written.

Remember that if you're using templates such as <nowiki>{{templatenamehere}}</nowiki>, a lot of them will not work unless the template has been copied over to here in the Template namespace. Bear that in mind if something doesn't work properly :)

[[Help:Video tutorial|{{resize|150%|You can find an EndMyopia Wiki specific, video tutorial here!}}]]

==Formatting==
===Using Wikitext===
====Wikilinks====
Try to use wikilinks when writing articles. You can write wikilinks like this:

<code><nowiki>[[Article]]</nowiki></code>

That will produce [[Article]]. You can also produce red links, that look [[MediaWiki:like this|like this]] - this is good for indicating to other editors that an article on this topic needs to be written, and doesn't exist yet.

====Wikitext guides====
You can find all the information you've ever wanted on how to use Wikitext to write articles effectively at Wikipedia.

[https://en.wikipedia.org/wiki/Help:Wikitext Wikipedia help article on how to format articles using Wikitext (very recommended)]

====Styling of articles====
You can find a far, far better crafted Manual of Style at Wikipedia than we could ever have the time or enthusiasm to write. [https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style Here it is, in all of its glory].

Definitely feel free to ignore anything that is more related to being an encyclopedia, we are not an encyclopedia, we are a vision improvement resource, first and foremost, full of funny jokes. You will find a lot of information about how to stylise articles in a cool way there though.
====Writing maths====
To write maths, enclose text in <code><nowiki><math></math></nowiki></code> tags.

<code><nowiki><math>(5+12)/(41.9999)</math></nowiki></code> displays as

<math>(5+12)/41.9999</math>

You can use fancy formatting too!

<code><nowiki><math>\frac{1}{2}e^{i\pi} = \frac{-1}{2}</math></nowiki></code> displays as

<math>\frac{1}{2}e^{i\pi} = \frac{-1}{2}</math>

For way too much detail on how to write and display formulae, see [https://en.wikipedia.org/wiki/Help:Displaying_a_formula Wikipedia's guide on how to render mathematical formulae].

====Citing papers====
We want to cite scientific research where possible to justify this approach. One way is to use the ''''proveit'''' gadget that should appear in the bottom right corner while editing - see the video tutorials mentioned above for more details.

=====Biomedical citation maker=====
Another (external) tool is http://sumsearch.org/cite/ - if you have a unique reference for the journal in one of various formats (such as a <nowiki>https://doi.org/...</nowiki> url), you can enter that into the box and will generate a fancy '''<nowiki><ref>{{cite...}}</ref></nowiki>''' sequence with title, authors, journal, etc. that you can simply paste in.

It provides a bookmarklet which allows you to generate a citation by simply selecting the doi using mouse, and pressing a button.

====EndMyopia specifics====
There is an apparent consensus at the time of writing that 'EndMyopia' should be the consistent capitalisation of how the name is referenced. Please refrain from using different capitalisations when referring to EndMyopia in articles. Consistency is important.

==Creating new pages==
===Creating a new article===
To create a new article, enter in the URL of the article you would like to create. You'll be taken to a page where you will be asked to create the article if it doesn't exist already.

Alternatively, create a redlink, [[MediaWiki:like this|like this]]. Then click on the redlink to create the article. You can place loads of redlinks in articles that are already written to indicate to others the articles that need writing.
===Creating a redirect===
Redirects move anyone who lands at that page to another page. This is used for terms that are similar, like [[Myopia]] and [[Shortsightedness]]. This is really important in preventing duplicate articles covering the same topic, and to aid in navigation of the wiki.

To create a redirect, type the following in the entire body of an article, and nothing else:

<code><nowiki>#redirect [[ArticleName]]</nowiki></code>

==Using talk pages==
Talk pages are 100% completely identical to normal pages in how they work. You can use all wikitext markup tricks in talk pages, the software does not handle them differently. The following are the basics:

Create subject headers using <code><nowiki>==Subject==</nowiki></code>. Indent your messages in responding to other editors using colons. Sign off your posts with your signature of <nowiki>~~~~</nowiki> as standard. Be sure to notify users using the template <code><nowiki>{{re|User}}</nowiki></code>. For example, a fictional conversation between two editors you might find on the Differentials talk page:

<code><nowiki>==Difference between diffs and normalised==</nowiki><br>
<nowiki>Hey guys, what should be the advice given about differentials? ~~~~</nowiki><br>
<nowiki>:{{re|User}} Differentials should be 1-2 diopters below your normalised prescription. We should put this in the lead section of the article. ~~~~</nowiki><br>
<nowiki>::{{re|OtherUser}} Oh great, many thanks! ~~~~</nowiki></code>

'''Will be rendered as (with the heading removed):'''

Hey guys, what should be the advice given about differentials? [[User:User|User]] ([[User talk:User|talk]]) 13:58, 20 May 2020 (UTC)
:{{re|User}} Differentials should be 1-2 diopters below your normalised prescription. We should put this in the lead section of the article. [[User:Other User|OtherUser]] ([[User talk:OtherUser|talk]]) 14:08, 20 May 2020 (UTC)
::{{re|OtherUser}} Oh great, many thanks! [[User:User|User]] ([[User talk:User|talk]]) 14:11, 20 May 2020 (UTC)

You can also press the 'Add topic' button so you don't have to type <code><nowiki>==Topic title==</nowiki></code> before your messages.

As you can see, using talk pages is ridiculously easy. Just remember though: [https://en.wikipedia.org/wiki/Help:Talk_pages anything you can do, Wikipedia can do better Click here for Wikipedia's explanation about talk pages.].
===Signatures===
Signatures can be configured using the Preferences button in the top right. It's better to keep this as simple as possible, and there's literally nothing wrong with the default signature. Definitely check out [https://en.wikipedia.org/wiki/Wikipedia:Signatures Wikipedia's page on how to customise signatures] if you want to leave your mark a bit more on every talk page you visit. Who doesn't like a colourful talk page?

Again, none of WPs policies apply to signatures, except please do not include images or files in your signatures as they cause unnecessary server load and make talk pages look horrible.

Posts can be signed off with four tildes or three. Four is by definitely what most people should use in most circumstances. Here's the difference:

<nowiki>~~~~</nowiki>
:[[User:User|User]] ([[User talk:User|talk]]) 14:08, 20 May 2020 (UTC)

<nowiki>~~~</nowiki>
:[[User:User|User]] ([[User talk:User|talk]])

Forgetting to use signatures will leave everyone confused really quickly, so please make it a habit to include <nowiki>~~~~</nowiki> at the end of all your messages on talk pages! :)

===Notifying other users===
When you reply to a user on any other talk page aside from their own talk page, they won't be notified unless you remember to send a notification template to them. This is super easy to do!!

When responding to people, type the following at the beginning of your message:

<code><nowiki>{{re|User}}</nowiki></code>

{{re|User}} is how it is displayed. This will send a notification to the user through the notification system.

You can also use <code><nowiki>{{u|User}}</nowiki></code>

{{u|User}} is how this one looks, and can be used to mention someone's username without the @ symbol.

{{Editing navbox}}
===Adding symbol messages===
{{main|EM:Symbol messages}}
You can add loads of funny symbol messages to what you say. Here are some examples.

{{done}}

{{WPcrystalball}}

{{Bulb}}{{Bulb2}}

{{Idea}}

{{NewProposal}}

{{Thank}}

See more at [[EM:Symbol messages]].

Resolving double vision

2020-06-14T04:30:53Z

Deadpan: Redirected page to Guide:Resolving double vision

#REDIRECT [[Guide:Resolving double vision]]

How to find Active Focus

2020-06-14T04:30:31Z

Deadpan: Redirected page to Guide:How to find Active Focus

#REDIRECT [[Guide:How to find Active Focus]]

Lower diopters

2020-06-14T04:23:24Z

Deadpan: Redirected page to Near-sightedness

#REDIRECT [[Near-sightedness]]

Guide:Resolving double vision

2020-06-14T04:22:54Z

Deadpan:

{{Under_construction}}

Help! I'm seeing double! Actually, [[double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[lower diopters]].

Ghosting

2020-06-14T04:19:55Z

Deadpan: Redirected page to Double vision

#REDIRECT [[Double vision]]

Misaligned Vision

2020-06-14T04:19:04Z

Deadpan: Redirected page to Double vision

#REDIRECT [[Double vision]]

Misaligned vision

2020-06-14T04:19:00Z

Deadpan: Redirected page to Double vision

#REDIRECT [[Double vision]]

Double Vision

2020-06-14T04:18:53Z

Deadpan: Redirected page to Double vision

#REDIRECT [[Double vision]]

Guide:Resolving misaligned vision

2020-06-14T04:18:36Z

Deadpan: Redirected page to Guide:Resolving double vision

#REDIRECT [[Guide:Resolving double vision]]

Guide:Resolving double vision

2020-06-14T04:17:30Z

Deadpan:

{{Under_construction}}

Help! I'm seeing double! Actually, [[Double vision]] is a good sign your vision is improving and is a normal step between blur and clarity, especially at [[low myopia|lower diopters]].

Guide:Resolving double vision

2020-06-14T04:16:20Z

Deadpan: Created the guide

{{Under_construction}}

Help! I'm seeing double! Actually, [[Double vision]] is a good sign your vision is improving and is a natural step between blur and clarity.

Double vision

2020-06-14T04:13:15Z

Deadpan:

'''Double Vision''', misaligned vision, or ghosting, is when your visual cortex perceives two images when there should be one.

This phenomenon usually occurs as an intermediate step in your vision improvement and is to be differentiated from [[Astigmatism]] ("Directional Blur"). Your vision biology is constantly adjusting to environmental stimulus, whereby different parts of your system respond at different rates. After clearing up [[Ciliary Spasm]] and after starting to improve the physical shape of your eyeball, your [[visual cortex]] already receives plenty of clear data. Our brains however were not built to handle artificial changes to the natural [[Focal Plane]]. This means that even when the image hitting your [[Retina]] is clear after reducing the strength of your glasses, your brain has to relearn how to create a single clear image out of this new data. This can take longer than resolving the refractive state of your eyeballs and manifests in multiple overlapping clear images of the same image.
This might be somewhat common as you start improving your eyesight - more ghosted images will begin to appear as your [[visual cortex]] is constantly learning to readjust to new signals.

Double Vision can be more pronounced once you are in the [[Low Myopia]] range, since every small change in your diopter strength then results in a larger shift of your [[Focal Plane]].

For help resolving double vision see the [[Guide:Resolving double vision]].
==References==
{{reflist}}

[[Category:Articles]]

Vertex distance

2020-06-14T03:53:03Z

Deadpan: /* Calculation */ Minor correction.

The '''vertex distance''' is the distance between the surface of your eye and the center back of your lens. As the lens moves further from the eye, the perceived strength of your lenses is altered. This is particularly important to know about when switching between contacts and eyeglasses, and for very high myopes.

==Practical Guidelines==

* <div> '''I have ''High Myopia''. How does Vertex Distance affect me?'''</div>
::If you wore contact lenses before EndMyopia (EM) and continue to use contact lenses throughout your EM journey - Then vertex distance doesn't affect you.

::If you wore glasses before EM and continue to wear glasses during EM then it is recommended to invest in a [[lens kit]] and choose your reduced lenses based on testing your [[visual acuity]] - Then vertex distance doesn't affect you. If you do not have access to a lens kit and you want to reduce in pre-defined diopter steps - Then vertex distance can affect you: For example, reducing from -14.0 dpt to -13.75 dpt at a vertex distance of 15mm results in an effective perceived diopter drop of only 0.17 dpt, further reducing to -13.5 dpt would result in an effective diopter drop of 0.34 dpt.

::If you switch from glasses to contact lenses at high myopia or vice-versa you definitely will need to account for vertex distance before buying new corrections.

* <div> '''I wear contact lenses as [[normalized]] and put [[plus lenses]] over them as my [[differentials]]. Do I need to worry about vertex distance?'''</div>
:No. Your differential correction will not undercorrect you by a diopter margin where vertex distance plays a role.

* <div> '''How do I measure my vertex distance?''' </div>
:Ask a second person to measure the distance from your closed eye to your glasses while you wear them. Or, as a literal "rule of thumb", try placing different fingers between your closed eye and the back of your glasses, then measure the thickness of your finger - This is an estimate for your vertex distance.

* <div> '''I use the endmyopia.org Diopter Calculator App and my results differ from my manual centimeter [[measurement]]s, why?''' </div>

:The [https://play.google.com/store/apps/details?id=org.endmyopia.calc Diopter Calculator App for Android] (as for the June 2020) measures the distance from the screen to the tip of your nose. Since the distance from the nose to your eyeball is not taken into account, your focal length seems smaller (and your diopters higher) than with a manual measurement. You can however correct these values by applying the same formula as for the vertex distance, inserting the distance from the tip of your nose to your eyeball for <math>x</math>.

==Calculation==
{{Notice|Advanced, this information may not apply. See above.}}
The effect of vertex distance on the perceived diopter strength of your glasses can be expressed by:

<math>D_C=\frac{1}{\frac{1}{D}-x}</math>,

where <math>D_C</math> is the corrected (perceived) diopter number, <math>D</math> is the diopter strength of your lenses and <math>x</math> is the vertex distance in meters. It is important to note here that this equation is sensitive to minus signs of your diopter strength.

Example for a vertex distance of 15mm (=0.015m):

<math>+4.0 dpt: D_C=\frac{1}{\frac{1}{+4.0}-0.015}=+4.255 dpt</math>

<math>-4.0 dpt: D_C=\frac{1}{\frac{1}{-4.0}-0.015}=-3.774 dpt</math>

In the above example the -4.0 dpt glasses yield the same level of correction as -3.75 dpt contact lenses. It can be seen that vertex distance '''increases''' the strength of [[plus Lenses]] and '''decreases''' the strength of [[minus lenses]]. The effect is noticeable above 4.0 dpt and is mostly negligible for [[low myopia]].

The expression looks less intimidating when you remember that (by definition) the [[diopter]] is the reciprocal of the focal length. So it's really just:

<math>f_C = f - x</math>
where <math>f_C = \frac{1}{D_C}</math> and <math>f = \frac{1}{D}</math>

Conceptually, the focus length is reduced (power is increased) because it has moved closer to the source of the image.

==References==
{{reflist}}

[[Category:Articles]]

Minus Lense

2020-06-10T22:14:40Z

Deadpan: Redirected page to Minus Lenses

#REDIRECT [[Minus Lenses]]

Guide:Reading glasses prescriptions

2020-06-10T22:10:48Z

Deadpan: /* Cylinder */ Swapped the axis on the table.. it is easier to read now in my opinion.

{{Under_construction}}
How do you read these complicated things!? Believe it or not, they're actually pretty simple to understand.

==Spherical==
[[Spherical]] is the overall correction, in all directions. It is measured in [[diopters]]. A minus value means the lense is used correct [[myopia]] and a plus value means it is used to correct [[presbyopia]].

==Cylinder==
[[Cylinder]] is the additional correction in a specific direction of your eye. It is measured in [[diopters]]. Think of a straight line going across the surface of your eye at a certain degree. The degree this happens at is your axis.

Cylinder correction means your eye has some level of [[astigmatism]].

Since cylinder correction is in addition to spherical correction, what the cylinder correction does depends on the spherical correction:
{| class="wikitable"
|+ Effect of including cylinder correction
! !! Minus Sphere !! Plus Sphere
|-
! Minus Cyl
| Increases myopia correction || Decreases presbyopia correction
|-
! Plus Cyl
| Decreases myopia correction || Increases presbyopia correction
|}

==Axis==
[[Axis]] is the degree at which cylinder values are relevant. The correct cylinder value but the wrong axis value would make the correction pretty worthless! When reducing your correction, you should never ever change the axis, especially if you've had that value of axis for a long time.

If you don't have any cylinder correction, you will not have an axis value either.

==Prism==

[[Category:Guides]]