What does power index of eye means?!
Question:
What does power index of eye means?
esp. compared to 20/20 etc and how about when one said his left eye is 100 degrees.
Answers:
20/20 means you can see at 20 feet what a "normal" person does at 20 feet. 20/50 means you can see at 20 feet what a "normal" person sees at 50 feet and so forth.
I'm not sure what is meant by degrees. Typically when the strength of glasses discussed, the term "diopters" is used. Typically a person who is +/- diopter will see at 20/40 or so without their glasses.