And is there any way to convert one to the other? I’m not sure how they’re each affected by things like astigmatism. Thanks in advance for any answers!
In: Biology
The -6 value is in units of diopters. This is a unit of lens refraction, not really about visual acuity.
The 20/20 is a measure of relative readability. There is a relationship, ignoring astigmatism. -1 diopters is 20/40; -2 is 20/80; -3 is 20/160 (usually 20/150 because that’s a row on the chart); -4 is 20/300. Beyond that, things get a little more complex because the myopia requires more correction to compensate for the relatively constant distance from the eye to the lens.
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