The lens of the eye would never be able to focus at varying distances or in varied light settings if the iris muscles did not work. Well if we never had the iris we would need some sort of design for the eye to do the job of focusing and adjusting to the light but God did a good enough job by giving us the iris and a lot of other mechanics of the eye.
iris and ciliary muscles
The opening that is controlled by the muscles of the iris is called the pupil. The iris is responsible for adjusting the size of the pupil in response to different lighting conditions.
The radial and circular muscles of the iris.
There are a number but one example are the muscles of the intestines (which undergo peristalsis), another example would be the muscles in the iris of the eye.
It is called the iris
When suddenly exposed to bright light, your pupils will automatically constrict (actually the constrictor muscles of the iris will contract, causing the iris to expand and narrow the pupil). Also, it is likely your eyelids will squint shut.
The iris of the eye has two main types of muscles - the radial muscle and the sphincter muscle. The radial muscle lies on the outside of the iris, and the sphincter muscle surrounds the pupil, allowing it to dilate and contract.
he was mean when he didnt see girls and he could be generous
The Iris contains the muscles that control Pupil size.
The IRISThe pupillary muscles located on the inner edge of the iris forms the outer boundary of the pupil. The ciliary muscles are located throughout the rest of the iris and into the ciliary body. The collarette is the region of the iris separating the pupillary muscle from the ciliary muscle. It also occupies the region where the sphincter muscle and dilator muscles overlap.
iris
Skeletal muscles, Adipocytes, Leukocytes and the Iris of the eye.