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Iridocyclitis is inflammation of the iris and ciliary body with inflammation predominantly confined to the ciliary body. Between 66% and 90% of uveitis cases are anterior in location (iritis). [ 4 ] This condition can occur as a single episode and subside with proper treatment or may take on a recurrent or chronic nature.
Choroidal nevus (plural: nevi) is a type of eye neoplasm that is classified under choroidal tumors as a type of benign (non-cancerous) melanocytic tumor. [1] A choroidal nevus can be described as an unambiguous pigmented blue or green-gray choroidal lesion, found at the front of the eye, around the iris, [2] or the rear end of the eye.
Melanin, a dark colored pigment, helps the choroid limit uncontrolled reflection within the eye that would potentially result in the perception of confusing images. In humans and most other primates, melanin occurs throughout the choroid. In albino humans, frequently melanin is absent and vision is low.
When this area of the eye is damaged, it leads to a gradual loss of sharp central vision, seeing dark spots, distorted or wavy vision and difficulty seeing colors. In these ways, "AMD can severely ...
There are three pigment colors that determine, depending on their proportion, the outward appearance of the iris, along with structural color. Green irises, for example, have some yellow and the blue structural color. Brown irises contain more or less melanin. Some eyes have a dark ring around the iris, called a limbal ring.
Central heterochromia is also an eye condition where there are two colors in the same iris; but the arrangement is concentric, rather than sectoral. The central (pupillary) zone of the iris is a different color than the mid-peripheral (ciliary) zone. Central heterochromia is more noticeable in irises containing low amounts of melanin. [32]
The root of the iris is the thinnest and most peripheral. [4] The muscle cells of the iris are smooth muscle in mammals and amphibians, but are striated muscle in reptiles (including birds). Many fish have neither, and, as a result, their irises are unable to dilate and contract, so that the pupil always remains of a fixed size. [5]
There’s a shirt that depicts three clenched fists raised in solidarity on sale at the Black Lives Matter store, and the enduring symbol is echoed in the organization’s mission statement ...