The eye focuses by
A) moving the lens.
B) moving the retina.
C) moving both the lens and the retina.
D) changing the focal length of the lens.
E) changing the index of refraction of the vitreous fluid.

Question

Quizplus · Accepted Answer

The eye focuses by changing the focal length of the lens. When the ciliary muscles surrounding the lens contract, the lens becomes thicker, increasing its refractive power and allowing the eye to focus on near objects. When the ciliary muscles relax, the lens becomes flatter, decreasing its refractive power and allowing the eye to focus on far objects. This process is known as accommodation. The other options (A, B, C, E) are not correct because they do not accurately describe how the eye focuses.

The Eye Focuses by