What is the function of the crystalline lens?

• A. Helps regulate intraocular pressure
• B. Produces aqueous humor
• C. Detects light intensity
• D. Allows accommodation for near objects

Answer: (D)

Accommodation is the eye’s adjustment for sharp focus at different distances. The crystalline lens enables near focus by changing its shape: when you look at something close, the ciliary muscle contracts, releasing tension on the zonular fibers and allowing the lens to become more curved. This increased curvature raises the eye’s refractive power so light from near objects is focused on the retina. For distant objects, the ciliary muscle relaxes, the zonules tighten, and the lens flattens, reducing its focusing power. The lens’s main role is dynamic focusing; it does not produce aqueous humor or regulate intraocular pressure, and it does not detect light intensity—that’s the retina’s job.