3 votes
Accepted

Why are there different perscriptions for glasses and contacts? Help me see eye to eye on this

Partly the additional sizing information required for contacts (Diameter and curvature of the cornea are needed for contact lenses but not for glasses) and the power also changes because the physical ...
  • 1,242
2 votes

Why do optometrists recommend dilation when the power of a lens can be measured even by a ruler?

The value of dilation of the pupil far outweighs the inconvenience.In fact, I'd offer that if an exam is done without it, you potentially lose the following: --full access to all the structure of the ...
1 vote

What would be visual acuity of a person if he can can read all letters of 20/25 and most of 20/20 on Snellen chart?

If the patient cannot read only minority of the letters in a line. Then the visual acuity(VA) is recorded as: 20/x-no. of letters not read where x is the line which the patient is reading. And when ...
1 vote

What would be visual acuity of a person if he can can read all letters of 20/25 and most of 20/20 on Snellen chart?

The 20:S notation means that a person with normal vision standing S feet away can see that line on the Snellen chart clearly, but fails to see smaller lines. Size of Letters Required for Visibility ...
  • 1,503

Only top scored, non community-wiki answers of a minimum length are eligible