Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q91 (NDA-II/2013) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Human anatomy physiology Answer Verified

Presbyopia is a visual defect caused by

Result
Your answer: —  Â·  Correct: C
Explanation

Presbyopia is an age-related visual defect characterized by the progressive loss of the eye's ability to focus on nearby objects. This condition primarily arises due to two physiological changes: the gradual weakening of the ciliary muscles and the diminishing flexibility or hardening of the crystalline lens [2]. In a healthy eye, the ciliary muscles contract to increase the lens's curvature for near vision [1]. However, as the eye ages, the lens loses its elasticity and becomes stiffer, while the ciliary muscles may experience a reduction in contractile power. This combined effect reduces the eye's accommodative amplitude, making it difficult to focus light from close objects onto the retina. Unlike myopia, which involves eyeball elongation, or hypermetropia, presbyopia is specifically linked to these age-related structural alterations in the lens and its supporting muscular apparatus [2].

Sources

  1. [2] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > Figure 10.3 > p. 164
  2. [1] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > 10.1.1 Power of Accommodation > p. 162
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
50%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

CDS-II · 2023 · Q22 Relevance score: 3.43

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: 1. Excessive curvature of the eye lens. 2. The eye-ball has become too small. 3. The focal length of the eye lens is too large. 4. Elongation of the eye-ball. Select the correct answer using the code given below:

CAPF · 2011 · Q48 Relevance score: 1.62

An elderly person while trying to read a book at about 25 cm from the eyes finds the imago appears blurred because of the decreasing effectiveness of the ciliary muscles and the loss of flexibility of the lens. This defect of the eyes is called

CDS-II · 2024 · Q92 Relevance score: -1.50

Which of the following statements for persons suffering from presbyopia is/are correct? 1. They cannot distinguish colours. 2. It usually develops with ageing. 3. They wear either bi-focal lenses consisting of both concave and convex lenses or progressive lenses. Select the answer using the code given below:

NDA-II · 2016 · Q27 Relevance score: -2.11

A person is unable to read a newspaper without his glasses. He is most probably suffering from

NDA-II · 2025 · Q73 Relevance score: -2.19

A person can see nearby objects clearly but cannot see distant object distinctly, the person is suffering with