Q. A person can see objects clearly only upto a maximum distance of 50 cm. His eye defect, nature of the corrective lens and its focal length are respectively
A) Myopia, concave, 50 cm
B) Myopia, convex, 50 cm
C) Hypermetropia, concave, 50 cm
D) Catract, convex, 50 cm
Explanation
(a) Range of vision for healthy eye is 25 cm (near point) to $\infty$ (far point). If the person can see clearly only upto a maximum distance of 50 cm he is suffering from myopia (short sightedness). A shortsighted eye can see only nearer objects. This defect can be removed by using a concave lens of suitable focal length $f$ = 50 cm.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.