Name one of the common defects of vision and the type of lens used to remove it.

Explain why, when it is getting dark at night, it is impossible to make out the color of cars on the road.

Nocturnal animals (animals which sleep during the day and come out at night) tend to have wide pupils and lot of rods in their retinas. Suggest reasons for this.

Name the defect of vision in a person;

(a) whose near point is more than 25 cm away.

(b) whose far point is less than infinity

Which defect of vision can be rectified:

(a) by using a concave lens ?

(b) by using a convex lens?