Explain why, we cannot see our surroundings clearly when we enter a darkened cinema hall from bright sunshine but our vision improves after some time.

How many plane mirror strips are there in a kaleidoscope? How are they arranged?

How does eye adjust itself to deal with light of varying intensity?

How does the eye-lens differ from the ordinary convex lens made of glass?

Name the part of the eye:

(a) which controls the amount of light entering the eye.

(b) which converges light rays to form the image.

(c) on which image is formed.

(d) which carries the image to brain.

(e) which changes the curvature (or thickness) of eye-lens to focus objects lying at various distances.