How does the lens of the human eye change shape to focus on near and far objects?

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Diagram of a horizontal section of the human eye showing labeled parts including the cornea, iris, lens, retina, sclera, optic nerve, and blood vessels, with internal structures and muscles visible. — human eye A horizontal cross section of the human eye, showing the major parts of the eye, including the protective covering of the cornea over the front of the eye.

The human eye's lens changes shape to focus on objects at different distances through a process called accommodation. When viewing distant objects, the ciliary muscle relaxes, causing the suspensory ligaments to pull the lens flatter. Conversely, for near objects, the ciliary muscle contracts, relaxing the ligaments. This allows the elastic lens to bulge and increase its curvature, enhancing its focusing power to bring the image sharply onto the retina. This adjustment is an involuntary reflex controlled by the autonomic nervous system.1234