SSC CGL
MediumQ. No. which-part-of-the-eye-focuses-light-on-the-retina
Which part of the eye focuses light on the retina?
Last Updated:
ACornea
BIris
CLens
DPupil
Correct Answer: LensYour Answer: C
✅ Correct Answer: C — Lens
The lens of the eye is a transparent, biconvex structure located behind the iris and pupil. Its primary function is to focus light precisely on the retina (the light-sensitive layer at the back of the eye). The lens achieves this through a process called accommodation — it changes its shape (becomes more curved for near objects, flatter for distant objects) by the action of ciliary muscles. When ciliary muscles contract, the lens becomes rounder (more convex) for near vision; when they relax, the lens flattens for far vision. Light first passes through the cornea (which provides most of the refraction), then through the lens which fine-tunes the focus onto the retina.
❌ Why other options are wrong:
• A. Cornea — The cornea is the transparent outer layer of the eye that provides the major part of the eye's refracting power. However, it cannot change shape, so it cannot perform accommodation (adjustment for near/far vision).
• B. Iris — The iris is the colored, circular part of the eye that regulates the size of the pupil (amount of light entering the eye). It controls light entry, not focusing.
• D. Pupil — The pupil is simply an opening (hole) in the center of the iris that allows light to enter the eye. It is not a physical structure that can focus light — it only regulates the amount of light entering.
📝 Important Note: Parts of the eye and their functions — Cornea: refracts light; Lens: focuses light (accommodation); Iris: controls pupil size; Retina: contains photoreceptors (rods=dim light, cones=color); Optic nerve: transmits signals to brain. Defects: Myopia (short-sightedness) = concave lens; Hypermetropia (far-sightedness) = convex lens. SSC CGL commonly asks about eye parts and their functions.
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