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:

The condition described is myopia (nearsightedness), where a person can see near objects clearly but distant objects appear blurred [1]. This refractive defect occurs because the image of a distant object is focused in front of the retina rather than directly on it [1]. The primary physiological causes for this are: (1) excessive curvature of the eye lens or cornea, which increases the refractive power, and (2) elongation of the eyeball (axial myopia), meaning the distance between the lens and the retina is too long. Conversely, a small eyeball or a focal length that is too large (insufficient converging power) are characteristics of hypermetropia (farsightedness), where light focuses behind the retina [1]. Therefore, statements 1 and 4 are the correct reasons for the described defect.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > What you have learnt > p. 170