Answer:
to focus the light onto the retina
Step-by-step explanation:
The "eye" has many anatomical parts. One of which is the "lens," which is a transparent structure located behind the "iris" (the part of the eye with color). It allows light rays to be focused unto the retina (located at the back of the eye). Upon changing its shape, it allows the eye to see images clearly.
The lens deteriorates over time as the person ages. It can be replaced by surgery (Lens Replacement Surgery). This is common for people with "cataract," a condition when the lens becomes opaque.