No, the human eye is an organ. However, each eye has six muscles that control its movements: the lateral rectus, the medial rectus, the inferior rectus, the superior rectus, the inferior oblique, and the superior oblique.
No, it is not. From Wikipedia:
The Pupil is essentially a HOLE that is centered in the IRIS. So, as a hole it is really nothing. The Iris which forms the Pupil is a muscle. The Iris consists of two muscle groups, the sphincter pupillae, and the dilator pupillae. These muscles contract and expand the Pupil in response to light stimuli.
In response to the amount of light entering the eye, the ciliary muscles attached to the iris expand or contract the aperture at the center of the iris.
No,the muscle in the iris of eye is an involuntary muscle.
The two involuntary muscles that make up the front part of the eye are the iris and the ciliary body. The iris controls the size of the pupil, regulating the amount of light entering the eye. The ciliary body adjusts the shape of the lens, enabling the eye to focus on near or distant objects.
It is called the iris
The iris is located in your eye. It is at the located at the front of the eye and is next to the pupil. It is usually coloured (e.g. brown, green or blue are the most common).
Melanin. Color is caused by the amount and type of pigment in the iris of the eye.
The iris is made of connective tissue, smooth muscle fibers, and pigments that give the iris its color.
The iris gives the eye it's color. It is not a muscle.
it squishes it until it becomes so small that the naked eye can't see it. (he he he) (naked)
smooth muscle
eye lids' heart
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.
The iris is not at the back of the eye. The structure at the back of the eye (on the inside) is called the retina. That's the part that senses light. The iris is a structure at the front of the eye, consisting of a ring of muscle with an opening in the center, called a pupil. The iris can shrink the pupil, to admit less light, or expand the pupil to a larger size to admit more light. Eye color is deterimned by the iris. It is the only colorful muscle.
You can close your eyes or blink whenever you want to, but most of the time you blink several times per minute without thinking about it.
papilla constrictor muscle of iris diaphragm
Circular and Radius set of muscle fibers
Pupil controlled by iris which is in turn is controlled by cilliary muscle
There are many muscles in the eye that control it. The four major muscles are the superior and inferior rectus (control up and down movement) and the lateral and medial rectus (control outer and inner movement). There are also two minor muscles, namely the inferior oblique (controls motion up and out or "extorsion") and superior oblique (controls motion down and in or "intorsion"). In additional to muscle which control movement, the lens of the eye is attached to a muscle called the ciliary body which controls anatomic movements and shape/focusing power of the lens. As we get older, this process of focusing, or accommodation gets weaker and most adults over 40 require reading glasses (magnifiers). Finally, the iris or colored part of the eye is a muscle which can contract and expand and control the amount of light which enters the eye in various illuminated environments. Adam D Koenigsberg MD FACS www.eyemusclesurgery.com
The iris and the ciliary muscle