視力，視角與屈光度關聯性(理論性推估計算，僅供參考)
using the formula:
D = 10^(E / 2 + 1.25)
where D is the Snellen denominator in feet and E is the refractive error in diopters.
For instance, given a refractive error of 0.25 D,D = 10^(0.25 / 2 + 1.25) = 10^1.375 = 23.7
The size of the pupil, size of the object, and contrast of the object are just a few of the factors that can significantly impact visual acuity for a given refractive error
