Difference between revisions of Measurement

Jump to navigation Jump to search
m (copied over from getting started)
 
(14 intermediate revisions by 5 users not shown)
Line 1: Line 1:
:''See also:'' [[Guide:How to measure your eyesight]]
==Stay calm==


In general, your measurements actually change wildly within the day. They're mostly useful for checking that you're not going off track with habits changes, or for measuring relative changes in vision in different circumstances. (e.g. diet, time of day, and activity)


== cm Measurement ==
As far as what progress you can see, that appears to actually be fairly individual. You need to measure to learn about how you see things. But think of general changes on the span of multiple weeks, or even a month or so.
A simple test for your level of myopia is to hold a ruler up to your eye, and measure how far away you can still read text without [[blur]].  If you measure this distance in centimetres, this is your "cm measurement". The ideal precise measurement is from the surface of your eyeball, but this is obviously not safe, so measure from some facial structure near your eye.  Consistency is more important than accuracy, you want to be able to track your small changes over the course of a day, and larger changes over time.


[[Diopters]] = -100cm/cm measurement.
Measurements are a learning process, not a goal


This test is fairly accurate up to about -10 Diopters.  This is not corrected for [[vertex distance]], but below -4D vertex distance has no significant effect, and your [[normalized]] lenses should be a little low anyway.
== Centimeter Measurement ==
The cm measurement uses a basic optics formula to calculate the diopters of correction you need to see clearly long distance. 
# Hold a ruler up to your eye, and measure how far away you can still read text without [[blur]] in centimeters.  This is your "cm measurement".
#* The ideal precise measurement is from the surface of your eyeball, but this is obviously not safe, so measure from some facial structure near your eye.
#* Consistency is more important than accuracy, you want to be able to track your small changes over the course of a day, and larger changes over time.
# Calculate diopters from the measurement: [[Diopters]] = -100cm/cm measurement.
# If your result is stronger than -4D, and you wear glasses, you'll need to correct for [[vertex distance]] to convert this from contacts diopters to glasses diopters.
# If your result is stronger than -4, you'll likely have problems getting consistent readings since the margin for error is much smaller. For best results: please see: [[Guide:Measuring with differentials]].


== Trial Refraction ==
== Trial Refraction ==
If your vision is worse than -10D, you may need a [[trial lens kit]] to measure your own myopia, or you may just stick to professional [[optometrist]] exams.
If your myopia is high and/or complex, you may need a [[trial lens kit]] to measure your own vision, or you may just stick to professional [[optometrist]] exams.


<youtube>n2ku6gJ3z7E</youtube>
<youtube>n2ku6gJ3z7E</youtube>


== Tools ==
== Tools ==
* [[EndMyopia Diopter Calculator]]
* [[mainendmyopiasite:focal-calculator/calc.html|EndMyopia Diopter Calculator]]
** [https://endmyopia.org/another-diy-diopter-measuring-tool/ Making the physical measurement easier]
** [https://endmyopia.org/another-diy-diopter-measuring-tool/ Making the physical measurement easier] (EndMyopia blog link)
*[[Varakari's Vision Log Tool]]
*[[Varakari's Vision Log Tool]]
* [https://endmyopia.org/focal-calculator/calc.html EndMyopia cm calculator]
* [https://endmyopia.org/measure/ Measurement] (EndMyopia blog link)
* [https://endmyopia.org/measure/ Measurement]
* [https://testflight.apple.com/join/wuAvRvdL The iOS Sight Meter App]
* [https://testflight.apple.com/join/wuAvRvdL The iOS Sight Meter App]
* [https://play.google.com/store/apps/details?id=org.endmyopia.calc The Android Diopter Calculator]
* [https://play.google.com/store/apps/details?id=org.endmyopia.calc The Android Diopter Calculator]
* [https://courses.endmyopia.org/wp-content/uploads/2024/03/endmyopia-myopia-ruler-letter-size.pdf Printable diopter ruler] (From the blog)
==See Also==
* [[Astigmatism measurement]]
* [[Guide:How_to_measure_your_eyesight|How_to_measure_your_eyesight]]
* [[Guide: measuring with differentials| Guide to measuring with Differentials for high myopes]]


==References==
==References==
{{reflist}}
{{reflist}}[https://courses.endmyopia.org/measure/?fbclid=IwAR01yIImN77PO3L1yU0LpTTxfW11uIRSFAbj9KoB53_2KxOP_hrZjoQYYDk Blog post on measurment]
[[Category:Articles]]
[[Category:Articles]]

Latest revision as of 18:37, 1 March 2024

See also: Guide:How to measure your eyesight

Stay calm

In general, your measurements actually change wildly within the day. They're mostly useful for checking that you're not going off track with habits changes, or for measuring relative changes in vision in different circumstances. (e.g. diet, time of day, and activity)

As far as what progress you can see, that appears to actually be fairly individual. You need to measure to learn about how you see things. But think of general changes on the span of multiple weeks, or even a month or so.

Measurements are a learning process, not a goal

Centimeter Measurement

The cm measurement uses a basic optics formula to calculate the diopters of correction you need to see clearly long distance.

  1. Hold a ruler up to your eye, and measure how far away you can still read text without blur in centimeters. This is your "cm measurement".
    • The ideal precise measurement is from the surface of your eyeball, but this is obviously not safe, so measure from some facial structure near your eye.
    • Consistency is more important than accuracy, you want to be able to track your small changes over the course of a day, and larger changes over time.
  2. Calculate diopters from the measurement: Diopters = -100cm/cm measurement.
  3. If your result is stronger than -4D, and you wear glasses, you'll need to correct for vertex distance to convert this from contacts diopters to glasses diopters.
  4. If your result is stronger than -4, you'll likely have problems getting consistent readings since the margin for error is much smaller. For best results: please see: Guide:Measuring with differentials.

Trial Refraction

If your myopia is high and/or complex, you may need a trial lens kit to measure your own vision, or you may just stick to professional optometrist exams.

Tools

See Also

References

Blog post on measurment