Which part of the eye is responsible for focusing light onto the retina?

The lens of the eye is responsible for focusing light onto the retina. It is a transparent, flexible structure located behind the iris and the pupil. The lens changes shape to adjust its focal distance, allowing us to see objects clearly at various distances — a process known as accommodation. When light enters the eye, it first passes through the cornea, which provides most of the eye's total focusing power, but the fine-tuning of this focus, particularly for objects at varying distances, is performed by the lens. Therefore, the lens plays a crucial role in ensuring that the light converges correctly onto the retina, where visual information is then processed into signals sent to the brain.