What is the function of the lens muscle in the eye?

What is the function of the lens muscle in the eye?

• A. Iris controls the amount of light entering the eye
• B. Focuses light onto retina
• C. Detects light as rods and cones
• D. Allows the lens to change shape

Answer: (D)

The lens changes shape to adjust focus for near and far vision. The muscle involved, the ciliary muscle, sits in the ciliary body and contracts to loosen the zonular fibers, making the lens thicker and more curved so it can refract light strongly for nearby objects. When you look at something distant, the muscle relaxes, the zonules pull tighter, and the lens becomes flatter to focus light from far away. The iris controls how much light enters, and the retina’s rods and cones detect light, but the specific role of the lens muscle is to enable the lens to change shape and adjust focus.

The lens changes shape to adjust focus for near and far vision. The muscle involved, the ciliary muscle, sits in the ciliary body and contracts to loosen the zonular fibers, making the lens thicker and more curved so it can refract light strongly for nearby objects. When you look at something distant, the muscle relaxes, the zonules pull tighter, and the lens becomes flatter to focus light from far away. The iris controls how much light enters, and the retina’s rods and cones detect light, but the specific role of the lens muscle is to enable the lens to change shape and adjust focus.