Intrinsic Eye Muscles: Function & Role in Vision

Intrinsic eye muscles are small muscles within the eye that control the movements of the lens and iris.

There are two types of intrinsic eye muscles: The ciliary body has muscle fibers that contract and relax to change the shape of the lens. This action adjusts the eye’s focus for near or distant objects. The Iris has muscle fibers that constrict and dilate the pupil. This action controls the amount of light that enters the eye and helps regulate the eye’s overall sensitivity.