Distinguish between:

Farsightedness and Nearsightedness

Give scientific reasons:

a. Simple microscope is used for watch repairs.

b. One can sense colours only in bright light.

c. We cannot clearly see an object kept at a distance less than 25 cm from the eye.

Explain the working of an astronomical telescope using refraction of light.

Distinguish between:

Concave lens and Convex Lens

What are the function of iris and the muscles connected to the lens in the human eye?