F.2 I.S Long & short sight

1. when long- sighted people see a near object, the
image will be formed beyond the retina. so we have to
use a convex lens to converge the light so that the image
will be formed on the retina.
2. when short-sighted people see a distant object, the
image will be formed in front of the retina. so we have
to use a concave lens to diverge the light so that the image
will be formed on the retina.