Difference between revisions of Guide:Reducing differentials
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===Simple way=== | ===Simple way=== | ||
The EndMyopia process will probably involve a lot of trial and error. Bearing this in mind, Jake recommends you reduce from your glasses prescription by about '''1.25 diopters'''.<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> This will depend on the distance you work from the screen, so reduce it by less if you work farther from the screen. Between 1-2 diopters is a good range - anything more than that and you'll probably want to double check it's a good idea. | The EndMyopia process will probably involve a lot of trial and error. Bearing this in mind, Jake recommends you reduce from your glasses prescription by about '''1.25 diopters'''.<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> This will depend on the distance you work from the screen, so reduce it by less if you work farther from the screen. Between 1-2 diopters is a good range - anything more than that and you'll probably want to double check it's a good idea. | ||
===Simple way with math=== | |||
1. Measure the distance to your monitor (in centimeters). | |||
2. Convert that number to diopters. | |||
3. Subtract the number you just got from your full prescription. | |||
===Complicated way with math=== | ===Complicated way with math=== | ||
The base point is an [[emmetropic eye]] with 20/20 vision. | The base point is an [[emmetropic eye]] with 20/20 vision. | ||
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Then, take the difference and subtract it from your full strength prescription glasses. ''Voila!'' you have a differential prescription. | Then, take the difference and subtract it from your full strength prescription glasses. ''Voila!'' you have a differential prescription. | ||
<div>'''More explanation at [https://wiki.endmyopia.org/wiki/Optics_related_math#Calculating_correction Optics-Related Math > Calculating Correction].'''</div> | |||
===Example=== | ===Example=== | ||
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So, you should use OD/OS -2.5/-1.5, if 57cm is the main distance you perform [[close-up activity]]. Simple! | So, you should use OD/OS -2.5/-1.5, if 57cm is the main distance you perform [[close-up activity]]. Simple! | ||
If you get a positive number, read the caveats about [[plus lenses]]. | === Plus === | ||
If you have [[low myopia]] and get a positive number, don't wear any glasses for close-up work, and read the caveats about [[plus lenses]]. | |||
==References== | ==References== | ||
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== See also == | == See also == | ||
* [[Guide:Reducing lens complexity]] | * [[Guide:How to measure your eyesight | How to measure your eyesight]] | ||
* [[Guide:Reducing normalized]] | * [[reduction | Reduction]] | ||
* [[Guide: | |||
* [[Differentials]] | |||
* [[Guide:Reducing lens complexity | Reducing lens complexity]] | |||
* [[Guide:Reducing normalized | Reducing normalized]] | |||
* [[Guide:Not_reducing_too_quickly | Take it slow]] | |||
[[Category:Guides]] | [[Category:Guides]] | ||