Assertion (A) : A person suffering from myopia uses a concave lens. Reason (R) : A concave lens diverges a beam of light incident on it.

Assertion (A) is true because myopia, or nearsightedness, is a refractive error where light focuses in front of the retina rather than on it, necessitating the use of a concave lens for correction [t5][t6]. Reason (R) is also true as a concave lens is fundamentally a diverging lens that spreads out incident light rays [c3][t3]. The reason correctly explains the assertion because in a myopic eye, the converging power is too high; a concave lens diverges the incoming parallel rays before they enter the eye [t1][t4]. This divergence effectively extends the focal length, allowing the eye's lens to focus the image precisely on the retina instead of in front of it [t1][t7]. Thus, the diverging property of the concave lens is the specific mechanism that enables the correction of myopia [t4].

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 10: Light: Mirrors and Lenses > Activity 10.10: Let us investigate > p. 164