Question

Collect information about lenses available in optical shop

Answer 1

1. Convex lenses : 
     People suffering from farsightedness or hypermetropia 
2. Concave lenses:
         People suffering from shortsightedness or myopia 
3. Cylindrical lenses:
          People suffering from astigmatism

Also, bifocal lenses with two lenses combined in one spectacle.

Hope this helps..!!