Question map
Which one among the following statements related to human eye is correct? (a) For a person suffering from short-sight defect, the image of a distant object is focused behind the retina. (b) Short-sight defect can be corrected by a converging spectacle lens. (c) For a person suffering from long-sight defect, the image of a near object is focused behind the retina. (d) Long-sight defect can be corrected by a diverging spectacle lens.
Explanation
In human vision, long-sight defect (hypermetropia) occurs when the eyeball is too short or the lens is too thin, causing the image of near objects to be focused behind the retina [2]. This condition is corrected using a convex lens, which is a converging lens that brings the focal point forward onto the retina. Conversely, short-sight defect (myopia) occurs when the image of distant objects is focused in front of the retina [2]. Myopia is corrected using a concave lens, which is a diverging lens that spreads light rays outward to move the focal point back onto the retina [1]. Therefore, statement (c) is correct as it accurately describes the focal position in hypermetropia, while statements (a), (b), and (d) incorrectly describe the focal points or the lens types required for correction.
Sources
- [2] https://www.ncbi.nlm.nih.gov/books/NBK470669/
- [1] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > What you have learnt > p. 170