What is long-sightedness? State the two causes of long-sightedness (or hypermetropia). With the help of ray diagrams, show:
(i) the eye-defect long-sightedness.
(ii) correction of long-sightedness by using a lens.
The defect of vision due to which a person cannot see the nearby objects clearly but he can see the distant objects clearly is known as long-sightedness.
The two causes of long-sightedness are:-
1) Focal length of the eye lens is too long.
2) The eyeball has become too small.
(i) The ray diagram is:-
(ii) The 3rd diagram shows the correction of long-sightedness by using a lens.