(a) State the reasons which lead to hypermetropia. With the help of suitable diagram explain this defect of vision and its correction. (b) Draw diagram of an experimental arrangement for observing scattering of light in colloidal solution. Name the two chemicals used in this activity.

(a) State the reasons which lead to hypermetropia. With the help of su

1.	(a) State the reasons which lead to hypermetropia. With the help of suitable diagram explain this defect of vision and its correction. (b) Draw diagram of an experimental arrangement for observing scattering of light in colloidal solution. Name the two chemicals used in this activity.
Answer» SOLUTION :(a) This defect arises either because : (i) the focal length of the eye lens is too long, or (ii) the EYEBALL has become too small. Such a person has to keep a reading MATERIAL much beyond 25 cm from the eye for comfortable reading. This is because the light rays from a nearby object are focused at a point behind the retina. Correction of Hypermetropia : (i) This defect can be corrected by using a convex lens of appropriate power. (ii) Eye-glasses with converging lenses PROVIDE the additional focusing power required for forming the image on the retina.