The iris (pl.: irides or irises) is a thin, annular structure in the eye in most mammals and birds that is responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Eye color is defined by the iris.

2024年7月24日 · The iris is the part of your eye that’s colored. It’s flat and round. Your eye color depends on how much melanin (a naturally occurring pigment) your body makes and certain genes.

2025年2月18日 · iris, in anatomy, the colored muscular part of the eye surrounding the pupil, the small black opening in the center. The iris is located in front of the lens and behind the cornea . It is bathed in front and behind by a fluid known as the aqueous humor .

2024年10月22日 · The iris is the colored, muscular curtain of the eye. Located between the cornea and lens, the iris regulates how much light gets into the eye by dilating and constricting. Disorders that affect the iris can occur due to genetic abnormalities or other conditions.

2024年10月31日 · The iris is the colored part of the human eye and a component of the uvea (uveal layer or uvea coat). The uvea is a pigmented layer found between the retina and the sclera (white of the eye). In addition to the iris, the uvea also consists of the choroid and ciliary body. The choroid is a vascular layer found between the retina and the sclera.

2024年11月4日 · The iris is the colored part of the eye that controls the amount of light that enters into the eye. It is the most visible part of the eye. The iris lies in front of the crystalline lens and separates the anterior chamber form the posterior chamber. The iris in part of the uveal tract which includes the ciliary body that also lies behind the iris.

2023年4月29日 · Behind the anterior chamber is the eye’s iris (the colored part of the eye) and the dark hole in the middle called the pupil. Muscles in the iris dilate (widen) or constrict (narrow) the pupil to control the amount of light reaching the back of the eye.

In this post we discuss in detail the gross, microscopic and clinical anatomy of the Iris. The iris is the anterior most part of the uveal tract. It has 2 surfaces, anterior and posterior. There are 4 layers in iris namely the anterior limiting layer, iris …

Iris in humans, is the colored (typically blue or brown) area, with the pupil (the circular black spot) in its center, and surrounded by the white sclera. Overlying cornea is completely transparent so is not visible, except the high-gloss luster it gives the eye. Also pictured are the red blood vessels within the sclera.

2023年6月12日 · The iris is the circular coloured part of the eye. It is part of the vascular layer of the eye - the other two components are the choroid and the ciliary body. The central opening of the iris is the pupil. Within the iris there are smooth muscle fibers that control the size of the pupil.