Which statement about the lens is true?

• A. It focuses light onto the retina.
• B. It regulates intraocular pressure.
• C. It contains photoreceptors.
• D. It senses light intensity.

Answer: (A)

The lens’s main role is to focus light onto the retina. It is a transparent, flexible, biconvex structure located behind the iris, and it works together with the cornea to bend incoming light so that images form sharply on the photoreceptor layer. Through accommodation, its shape changes to adjust focus: when viewing near objects, the ciliary muscle contracts, reducing tension on the zonular fibers, and the lens becomes thicker to increase its refractive power; for distant objects, the muscle relaxes, the zonules tighten, and the lens flattens for a longer, less curved path of light.

Regulating intraocular pressure is a function of aqueous humor production and drainage systems, not the lens. The lens itself does not contain photoreceptors; those are located in the retina, which also detects light intensity.