Endmyopia Wiki - User contributions [en]

Astigmatism

2020-06-21T23:12:58Z

Lajos:

'''Astigmatism''' is a really annoying eye condition that means you have blur in a specific direction, or [[axis]] (technically, depending on the notation used for your prescription, the axis may indicate the angle of the eye's meridian where you have no astigmatism, and need no extra lens power, or the one where you have the most and need the most extra lens power). Astigmatism is compensated with [[cylinder]] lenses. A cylinder lens adds power along one particular meridian of the eye.

Astigmatism often reduces spontaneously as myopia is corrected.

==Understanding astigmatism==
Astigmatism is caused by an irregularly shaped cornea or lens. The first is called corneal astigmatism, which is the more common form, and the second is called lenticular astigmatism.

==Reducing astigmatism==
As with myopia, astigmatism should be tackled in small steps when selecting lenses for [[differential]] or [[normalized]] glasses. If only a small amount of cylinder correction is present, say 0.25 [[diopters]], the cylinder correction can be dropped, with no other changes. Otherwise, cylinder should be reduced in small increments. If sphere is being reduced, cylinder should not be changed at the same time, and conversely, if cylinder is being reduced then sphere should not be changed. The only time that both sphere and cylinder should be changed, is when converting to the spherical equivalent.

The '''spherical equivalent''' of cylinder lenses may be useful, to simplify the reduced lens path. 0.50 cylinder is equivalent to 0.25 sphere. For example, a full prescription of "-1.00 Sphere -1.50 Cylinder" could be converted to "-1.75 Sphere". The resulting spherical equivalent is not perfectly tailored for the astigmatic blur, so it leaves a small amount of "useful blur".

Regardless of how the myope reduces their lenses, the goal of each reduction is to have a small amount of "useful blur", to be cleared up with [[active focus]] and good habits.

==Resources==
*[https://endmyopia.org/the-definitive-guide-astigmatism/ EndMyopia Blog - The Definitive Guide: What Is Astigmatism]
*[https://endmyopia.org/tag/astigmatism-2/ EndMyopia Blog - all astigmatism articles]

==References==
{{reflist}}

[[Category:Articles]]
[[Category:Eye conditions]]

20-20-20 rule

2020-06-21T23:09:22Z

Lajos:

<big>
* Every 20 minutes
* Look at something 20 feet away (6 meters)
* For at least 20 Seconds</big>

The 20-20-20 rule is designed to be an easy to remember caution about doing too much [[near work]] and to give your eyes a break from [[eye strain]] regularly. This rule is supported by both conventional optometry<ref name="American Optometric Association 20-20-20 rule poster">{{Cite web |title=American Optometric Association 20-20-20 rule poster |date=2020-05-30 |website=American Optometric Association |url=https://www.aoa.org/documents/infographics/SYVM2016Infographics.pdf |access-date=2020-05-30}}</ref><ref name="Medical News Today: Does the 20-20-20 rule prevent eye strain?">{{Cite web |title=20-20-20 rule: How to prevent eye strain |url=https://www.medicalnewstoday.com/articles/321536 |last=Nall |first=Rachel |date=2020-05-30 |website=www.medicalnewstoday.com |language=en |access-date=2020-05-30}}</ref> and the EM method, although the EM method suggests that 20 seconds be five minutes.<ref>{{Cite web |title=Eye Strain Awareness: Prevent Pseudo Myopia - Endmyopia |url=https://endmyopia.org/breaks-are-key-to-build-eye-strain-awareness/ |last=Steiner |first=Jake |website=endmyopia.org |access-date=2020-06-01}}</ref>
In some countries, this may be known as the 10-10-10 rule which is similar, but goes as follows:

<big>

* Every 10 minutes
* Look at something 10 m away

* For at least 10 seconds

</big>

[[Category:Articles]]

Optometrist

2020-06-21T23:05:52Z

Lajos:

From the Greek Optos (what is seen) and -metry (to measure) an optometrist is a doctor, or in some countries a trained specialist, who measures your eye's refractive error, writes your [[prescription]] and screens for common eye health issues. Even if you are not using your prescription, you should see an optometrist on the schedule he recommends to screen for other health issues and objectively measure your progress. High [[myopes]] are at higher risk for many eye conditions and should see their optometrists more often than [[emmetropes]].

==References==
{{reflist}}

[[Category:Articles that are deletion or merge candidates]]

Myopia is Mental

2020-06-21T23:03:47Z

Lajos:

[https://www.myopiaismental.com/ Myopia is Mental]

[https://www.youtube.com/user/markhyo YouTube Channel]

'''Myopia is Mental''' is a vision improvement method created by Mark Warren.

An emphasis on [[peripheral vision]] is very good for relaxing the eyeball, and reduces [[tunnel vision]] in many cases.

The method has existed for less than a year (as of start of 2020) and lacks many of the details to improve vision in the majority of adherents, in the long term. Due to a reliance on [[clear flashes]], although some might have good results with it, the effect may be hard to reproduce consistently across many people. It also ignores the scientific consensus that [[myopia]] is caused by a longer [[axial length]] of the eyeball, and is not purely a psychological effect.

Do feel free to give it a go. Make your own mind up - be skeptical and avoid [[Blind belief]]. We'll still be here if you decide to come back.

[[Category:Unicorn Farming]]

Overcorrected

2020-06-21T22:59:03Z

Lajos: Created page with "One definition of being over-corrected is that your corrective lenses allow you to see better than an average non-myopic person i.e. you have better than 20/20 vision. It is n..."

One definition of being over-corrected is that your corrective lenses allow you to see better than an average non-myopic person i.e. you have better than 20/20 vision. It is not clearly defined at which ambient light level this is to be considered over-correction. However, it should be considered that opticians often prescribe lenses that correct you to at least 20/20 night vision on a 6m Snellen chart, therefore you may see better than 20/20 in bright sunlight without it being considered over-correction. If you can see better than 20/20 on a 6m Snellen chart at night with low levels of ambient light, it is probable that you are over-corrected.

20/20 correction

2020-06-21T22:53:29Z

Lajos:

'''''20/20 correction''''' is a correction you normally get from a licensed optician, which corrects your eyesight up to a degree of [[visual acuity]] that an [[emmetropic]] (or "normal-seeing") person achieves on a [[Snellen Chart]].

If you can see 20/15 or even better, this means that you are [[overcorrected]]. (It is not necessarily considered super-human acuity, but it is unnecessary to correct to this level.)

It is very difficult to perform [[Active Focus]] at this level of correction, as there is not enough of a [[blur horizon]] to produce [[stimulus]] - see [[Distance vision]].
==See also==
[[20/x vision]]

==References==
{{reflist}}

[[Category:Articles]]

20/x vision

2020-06-21T22:51:55Z

Lajos:

'''20/x''' vision (if x < 20) is vision that is better than [[20/20]]. It usually involves a small amount of [[hyperopia]].

==References==
{{reflist}}

[[Category:Articles]]
[[Category:Eye conditions]]

Optics related math

2020-06-21T22:50:21Z

Lajos:

[[File:Math guy with glasses.gif|right]]
Here's a page with maths related to diopters and glasses.

You don't really need to know any of this stuff to improve your eyesight, but it's good to know for deeper understanding {{smiley}}
__TOC__
{{clear}}
==Diopters are inverse meters==
''See Also [[Diopters]]''

''See Also [[cm Measurement]]''

Remember that 100cm = 1m.

<math>D = \frac{1}{meters}</math>

conversely

<math>meters = \frac{1}{D}</math>

==Point of refraction==
''See also [[Refraction]]''
{{#ev:youtube|9z2jjT_Gm7o|400}}

<math>s = distance\ to\ object</math> (meters)

<math>s' = distance\ to\ point\ of\ refraction</math> (meters)

<math>f = focal\ length\ of\ lens</math> (meters)

<math>P = power\ of\ lens</math> (diopters)

<math>\frac{1}{f} = (\frac{1}{s}) + (\frac{1}{s'})</math>

<math>\frac{1}{f} = P</math>

==Visual acuity equation==
<math>(\frac{font\ height}{distance\ to\ sign})(\frac{180}{pi}) \times 60 = arcminutes = a</math>

Note: 5Arcminutes = 20/20

Set up proportion: <math>\frac{a}{(\frac{20}{x})} = \frac{5}{(\frac{20}{20})}</math>

===Visual acuity (mm/metres)===
<math>\frac{font\ height (mm)}{distance\ to\ sign(m)} \times 13.75 = denominator \times of \frac{20}{x}</math>

===Visual acuity (in/feet)===
<math>\frac{font\ height(in)}{distance\ to\ sign(ft.)} \times 1146 = denominator \times of \frac{20}{x}</math>

With text that we are familiar with, the brain may clear up that text more than our vision would actually allow.<ref>{{cite jake|https://endmyopia.org/use-math-to-turn-any-text-into-your-own-impromptu-eyechart/}}</ref>

==Average axial length accomodation/rate of change==
<math>typical\ emmetropic\ eye = 25mm = 25,000\ microns</math>

<math>change\ in\ axial\ length\ of\ 1mm=3D</math>

If someone with typical eyes wanted to adapt say 20/20 to .25 less
normalized within 3-4 months
would need to decrease axial length 0.083mm
about 0.92microns/day - 0.69microns/day average
''Credit: [https://www.facebook.com/groups/endmyopia/permalink/759426960917375/ Mark Podowski]''
==Converting from Glasses to Contact Lens Prescription or vice-versa==
* [[Vertex distance]]
* [[Wikipedia:Vertex_distance|Vertex distance formula (also for astigmatism)]]

==References==
{{reflist}}

Optics related math

2020-06-20T22:55:12Z

Lajos: Reverted edits by NottNott (talk) to last revision by Lajos

[[File:Math guy with glasses.gif|right]]
Here's a page with maths related to diopters and glasses.

You don't really need to know any of this stuff to improve your eyesight, but it's good to know for deeper understanding {{smiley}}
{{clear}}
==Diopters are inverse meters==
''See Also [[Diopters]]''

''See Also [[cm Measurement]]''

Remember that 100cm = 1m.

<math>D = \frac{1}{meters}</math>

conversely

<math>meters = \frac{1}{D}</math>

==Point of refraction==
''See also [[Refraction]]''
{{#ev:youtube|9z2jjT_Gm7o|400}}

<math>s = distance\ to\ object</math> (meters)

<math>s' = distance\ to\ point\ of\ refraction</math> (meters)

<math>f = focal\ length\ of\ lens</math> (meters)

<math>P = power\ of\ lens</math> (diopters)

<math>\frac{1}{f} = (\frac{1}{s}) + (\frac{1}{s'})</math>

<math>\frac{1}{f} = P</math>

==Visual acuity equation==
<math>(\frac{font\ height}{distance\ to\ sign})(\frac{180}{60pi}) = arcminutes = a</math>

Note: 5Arcminutes = 20/20

Set up proportion: <math>\frac{a}{(\frac{20}{x})} = \frac{5}{(\frac{20}{20})}</math>

===Visual acuity (mm/metres)===
<math>\frac{font\ height (mm)}{distance\ to\ sign(m)} \times 13.75 = denominator \times of \frac{20}{x}</math>

===Visual acuity (in/feet)===
<math>\frac{font\ height(in)}{distance\ to\ sign(ft.)} \times 1146 = denominator \times of \frac{20}{x}</math>

With text that we are familiar the brain may clear up that text more than our vision actually operates at.<ref>{{cite jake|https://endmyopia.org/use-math-to-turn-any-text-into-your-own-impromptu-eyechart/}}</ref>

==Average axial length accomodation/rate of change==
<math>typical\ emmetropic\ eye = 25mm = 25,000\ microns</math>

<math>change\ in\ axial\ length\ of\ 1mm=3D</math>

If someone with typical eyes wanted to adapt say 20/20 to .25 less
normalized within 3-4 months
would need to decrease axial length 0.083mm
about 0.92microns/day - 0.69microns/day average
''Credit: [https://www.facebook.com/groups/endmyopia/permalink/759426960917375/ Mark Podowski]''
==Converting from Glasses to Contact Lens Prescription or vice-versa==
[https://en.wikipedia.org/wiki/Vertex_distance Vertex distance formula (also for astigmatism)]

Differentials

2020-06-20T22:52:43Z

Lajos:

[[File:Microsoft Cloud Event Dublin, upclose with graphs.jpg|thumb|Without ''diffs'', you're on the path to ever increasing prescriptions and will get nowhere with vision improvement :(]]
'''Differentials''' are reduced strength glasses for [[close-up|close up activity]]. They have a lower correction than your [[normalized]] lenses that allows you to see clearly only up to the screen. The difference between [[normalized]] and differential lenses is usually between 1 and 2 [[diopters]].<ref>{{cite jake|https://endmyopia.org/faq-items/what-is-the-differential-prescription/|What is the differential prescription?}}</ref><ref name=ChooseReduction>{{cite jake|https://endmyopia.org/choose-reduced-glasses-prescription-differential-close-friendly-glasses/|How To Choose A Reduced Glasses Prescription (Differential / Close-Up Friendly Glasses)}}</ref>

People with myopia of -2 D and lower do not typically need to wear differentials (because with -2 D your distance till blur should be around 50cm - far enough to see your screen with sufficient clarity).

If you are wearing contact lenses, it is recommended to use plus lenses of a suitable power over the contacts as differential glasses.
==Why are differentials worn?==
The primary stimulus for [[axial elongation]] of the eyeball is [[hyperopic defocus]], which occurs when someone:
* Is engaged in close-up activity
* Wears more correction than they need to when seeing the object that is close up.

Differentials allow the wearer to wear ''just what they need to'', to see up close. This removes the stimulus of hyperopic defocus, and stops eyes from getting more myopic. In a sense, it's a [[quick fix]]. {{wink}}

It's fairly easy to stop myopia from progressing, by just wearing differentials. The axial length of the eye does not randomly change by itself, it only changes in response to [[stimulus]].

== See also ==
[[Guide:Reducing differentials]]

==References==
{{reflist}}
[[Category:Articles]]

Optics related math

2020-06-20T20:51:20Z

Lajos:

[[File:Math guy with glasses.gif|right]]
Here's a page with maths related to diopters and glasses.

You don't really need to know any of this stuff to improve your eyesight, but it's good to know for deeper understanding {{smiley}}
{{clear}}
==Diopters are inverse meters==
''See Also [[Diopters]]''

''See Also [[cm Measurement]]''

Remember that 100cm = 1m.

<math>D = \frac{1}{meters}</math>

conversely

<math>meters = \frac{1}{D}</math>

==Point of refraction==
''See also [[Refraction]]''
{{#ev:youtube|9z2jjT_Gm7o|400}}

<math>s = distance\ to\ object</math> (meters)

<math>s' = distance\ to\ point\ of\ refraction</math> (meters)

<math>f = focal\ length\ of\ lens</math> (meters)

<math>P = power\ of\ lens</math> (diopters)

<math>\frac{1}{f} = (\frac{1}{s}) + (\frac{1}{s'})</math>

<math>\frac{1}{f} = P</math>

==Visual acuity equation==
<math>(\frac{font\ height}{distance\ to\ sign})(\frac{180}{60pi}) = arcminutes = a</math>

Note: 5Arcminutes = 20/20

Set up proportion: <math>\frac{a}{(\frac{20}{x})} = \frac{5}{(\frac{20}{20})}</math>

===Visual acuity (mm/metres)===
<math>\frac{font\ height (mm)}{distance\ to\ sign(m)} \times 13.75 = denominator \times of \frac{20}{x}</math>

===Visual acuity (in/feet)===
<math>\frac{font\ height(in)}{distance\ to\ sign(ft.)} \times 1146 = denominator \times of \frac{20}{x}</math>

With text that we are familiar the brain may clear up that text more than our vision actually operates at.<ref>{{cite jake|https://endmyopia.org/use-math-to-turn-any-text-into-your-own-impromptu-eyechart/}}</ref>

==Average axial length accomodation/rate of change==
<math>typical\ emmetropic\ eye = 25mm = 25,000\ microns</math>

<math>change\ in\ axial\ length\ of\ 1mm=3D</math>

If someone with typical eyes wanted to adapt say 20/20 to .25 less
normalized within 3-4 months
would need to decrease axial length 0.083mm
about 0.92microns/day - 0.69microns/day average
''Credit: [https://www.facebook.com/groups/endmyopia/permalink/759426960917375/ Mark Podowski]''
==Converting from Glasses to Contact Lens Prescription or vice-versa==
[https://en.wikipedia.org/wiki/Vertex_distance Vertex distance formula (also for astigmatism)]

Writing:Paint the blurry letters with your eyes

2020-06-20T20:43:38Z

Lajos: Created page with "{{Writing|author={{subst:REVISIONUSER}}}}  AF is one of those things where for some people like me it’s so obvious that I know when I’m exper..."

{{Writing|author=Lajos}}

AF is one of those things where for some people like me it’s so obvious that I know when I’m experiencing it. But for some others it’s subtle and they actually already got it but keep seeking for something dramatic.

I’m lucky enough to have experienced drastic temporary focus improvement up close but often all AF is is you looking at some slightly, or for some people quite blurry text (some people need more stimulus) and for me the trick is not to blink for a while, and you will notice it clears up and you can see edges sharp that you couldn’t before.

Try not to blink too soon else you might reset the eye that is just about to clear up that blur. As soon as you notice any small clarity improvement by staring then blinking you have found AF. Doesn’t need to be dramatic.

For some people - as Jake already posted on his blog - it helps to think of describing the blur. I personally like to think that I am “painting” the letters with my eyes - my gaze is the paintbrush - you have to cover each part of every letter.

As posted many times on the forum, if you have ciliary spasm it can be harder to get active focus working (but not impossible, as I found myself). So, the first thing, if you cannot get it, is always to get your differentials, as Jake suggests and use them for a month.

You might experience some stinging when trying to AF, because your ciliary spasm is getting in the way of your eye trying to focus. It might tear up. But after some blinking this should go away, with the ciliary spasm. You generally know you have ciliary spasm by e.g. looking into the distance with your normalised or naked eyes and not being able to look for too long before blinking - your eye cannot focus well - you can almost feel a resistance to trying to focus into the distance for any length of time. Once you resolve ciliary spasm you will be able to look much longer into the distance without any feeling of strain or needing to blink after a few short seconds…

Anyway, back to AF, for me, as I mentioned, the key was not blinking too soon when trying to clear up blur.

Once you have it, you might not get it again for days. Then the gaps will become fewer. Eventually you’ll be able to do it almost any time (when you don’t have ciliary spasm). You won’t need to think about describing the blur or painting letters with your eyes, you’ll just have to look for some seconds at the blurry text. When you get better, you can start on other objects, mostly edges, posts, places with high contrast or even counting leaves on trees - anything where your brain knows what it SHOULD look like and can correct the slight blur.


[[Category:Project AF]]