Question

What is hypermetropia? State the two causes of hypermetropia. With the help of ray diagrams, show:
(a) the eye-defect hypermetropia
​(b) correction of hypermetropia by using a lens

Answer 1

Hypermetropia or long-sightedness is a common eye defect, in which a person is not able to see nearby objects whereas the farther objects appear clear to the person.

Two causes of hypermetropia:

(i) Eyeball being too short.
(ii) The increased focal length of the eye lens.

(a) Hypermetropic eye:

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(b) Correction made with a convex lens for the hypermetropic eye: