Question

What is the function of iris and muscles connected to the lens in the human eye?

Answer 1

Human irises help in focusing on objects at different distances by a method called accomodation. The pupil size varies depending on which object the eyes are focusing. It helps in keeping the image formed on the retina sharp.

The anterior part of the choroid passes into the ciliary body, one function of which is anchoring the lens in place. The ciliary body contains a muscle (ciliary muscle), which can change the shape of the lens for adjustment to far or near sight, respectively, thereby controlling the so-called refractive power of the lens (accomodation). Additional functions of the ciliary body are the production, secretion, and outflow of aquaeous humour (the latter via the so-called „Schlemm’s canal“), a watery fluid that fills both the anterior and the posterior chambers of the eye