What part of the eye is responsible for focusing light?

The lens is the part of the eye responsible for focusing light onto the retina. It is a transparent, flexible structure located behind the iris and the pupil. The lens works in conjunction with the cornea to bend (refract) light rays, allowing them to converge on the retina, which is essential for clear vision. The ability of the lens to change shape—becoming thicker or thinner—enables it to focus on objects that are near or far away, a process known as accommodation. This capacity to adjust focus is crucial for the eye's function, as it allows for the perception of clarity and detail across different distances.

The other parts mentioned—such as the cornea, retina, and pupil—play important roles in vision, but they do not focus light in the same manner as the lens. The cornea provides the majority of the eye's total refractive power, while the pupil regulates the amount of light entering the eye. The retina is responsible for receiving the focused light and converting it into neural signals to be sent to the brain, but it does not contribute to focusing the light itself.