2023 · Q1
A person can see near objects clearly through his eyes but cannot see distant objects clearly. The possible reason(s) for this defect could be:
- 1Excessive curvature of the eye lens.
- 2The eye - ball has become too small.
- 3The focal length of the eye lens is too large.
- 4Elongation of the eye - ball.
Select the correct answer using the code given below:
General KnowledgePhysics
- A1 only
- B2 and 4 only
- C1 and 4 only
- D1 and 3 only
Explanation
Myopia (near-sightedness) makes distant objects blurry because their image forms in front of the retina. Excessive curvature of the eye lens (1) increases its converging power, pulling the image forward, while elongation of the eyeball (4) moves the retina farther from the lens with the same effect. A too-small eyeball (2) and a too-long focal length (3) instead cause hypermetropia, the opposite defect. Hence only statements 1 and 4 are possible causes.