Which eye structure changes shape to focus light on the retina?

Which eye structure changes shape to focus light on the retina?

• A. Cornea
• B. Pupil
• C. Iris
• D. Lens

Answer: (D)

The lens is responsible for changing shape to focus light on the retina through accommodation. When you look at something up close, the ciliary muscles contract, loosening the suspensory ligaments and making the lens more rounded, which increases its refractive power so near objects come into sharp focus. For distant objects, the ciliary muscles relax, the lens becomes flatter, and its focusing power decreases. The cornea provides most of the eye’s bending of light but its shape is relatively fixed, so it doesn’t adjust for focusing at different distances. The iris and pupil control how much light enters, not where the light is focused. So the lens is the structure that actively changes shape to focus light onto the retina.

The lens is responsible for changing shape to focus light on the retina through accommodation. When you look at something up close, the ciliary muscles contract, loosening the suspensory ligaments and making the lens more rounded, which increases its refractive power so near objects come into sharp focus. For distant objects, the ciliary muscles relax, the lens becomes flatter, and its focusing power decreases. The cornea provides most of the eye’s bending of light but its shape is relatively fixed, so it doesn’t adjust for focusing at different distances. The iris and pupil control how much light enters, not where the light is focused. So the lens is the structure that actively changes shape to focus light onto the retina.