Question

Fast plz ...........

Answer 1

(1)which defect of vision is represented in this case?

In the following picture we can see that the image of the object formed by the eye lens is behind the retina . this defect of vision is known as hypermetropia or far sightedness

(2)what could be the causes of this defect?

The eye lens becomes too thin due to which the person is unable to focus on the near by objects clearly

(3) with the help of a suitable diagram show how this defect can be corrected by the use of a suitable lens?

This defect can be removed by placing a convex lens between the object and the eye.

Convex lens with the right converging effect focuses the image of the nearby object on the retina

Extra information:

If the near point is at a distance by from the eye lens then the incident rays from the object at the least distance of distinct vision 25cm appear to be coming from near D after conversion from convex lens

u = -0.25 cm

v = - x cm

$\frac{1}{f} = \frac{1}{v} - \frac{1}{u}$

$\frac{1}{f} = - \frac{1}{y} + 0.25$

$\frac{1}{f} = - \frac{1}{y} + 4$

$f = \frac{y}{4y - 1} m$

the power of the convex lens required to correct the defect is

$p = \frac{4y - 1}{y} m$