Question

17. The near point of an elderly person is 50cm from the eye. Find the focal length and
power of the corrective lens used?​

Answer 1

Answer:

This defect of vision is corrected by using a convex lens. A convex lens of suitable power converges the incoming light. The given person will be able to clearly see the object kept at 25 cm (near point of the normal eye), if the image of the object is formed at his near point, which is given as 1 m.