A person cannot see the objects distinctly, when placed at a distance less than 50 cm

A person cannot see the objects distinctly, when placed at a distance less than 50 cm.
(a) Identify the defect of vision.
(b) Give two reasons for this defect.
© Calculate the power and nature of the lens he should be using to see clearly the object placed at a distance of 25 cm from his eyes.
(d) Draw the ray diagrams for the defective and the corrected eye.

(a) Hypermetropia.
(b) Either the hyperopic eyeball is too short or (ii) The ciliary muscle is unable to change the shape of the lens enough to properly focus the image i.e., the focal length of the eye lens is too long.

(d)