Observe the following figure and answer the questions given below :[Figure: a section of the eye with parallel rays entering the eye lens and converging to a point in front of the retina, then diverging to fall on the retina.](a) Name the defect of v…

Answer: (a) Myopia (short sight); (b) the eye lens is too converging or the eyeball is too long; (c) by a concave (diverging) lens of suitable power.

(a) The rays from a distant object meet in front of the retina, so distant objects appear blurred. This defect is myopia (nearsightedness).

(b) It is caused either by excessive curvature of the eye lens (the lens is too converging, i.e. its focal length is too small) or by elongation of the eyeball, so the retina lies behind the focal plane.

(c) A concave lens of suitable negative power is placed in front of the eye. It diverges the rays slightly before they enter the eye, so the eye lens can now focus them exactly on the retina. The far point of such an eye is less than infinity.

(d) Diagram: draw the eye with a concave lens in front of it. Show parallel rays from a distant object first diverging at the concave lens, then entering the eye lens and converging exactly on the retina. Label the concave lens, eye lens and retina.