1. An inflammation of part or all of the uvea: Uveitis commonly involves the other tunics of the eye, like the sclera, cornea, and retina. However nonuveal parts of the eye, including the retina and cornea, may also be concerned.
2. A nonspecific or general term for any intraocular inflammatory disorder or any part of the uveal tract: The uveal tract structures (iris, ciliary body, and choroid) are usually involved in uveitis, but other nonuveal parts of the eye, including the retina and cornea, may also be involved.

Uveitis that is not associated with known infections, or that is associated with diseases of unknown cause, is termed endogenous uveitis. This is thought to be due to an autoimmune phenomenon.

The patient may experience varying degrees of discomfor or pain, with or without blurring of vision.

In many cases a cause is never found, however some known associations include various types of arthritis, some bowel diseases, virus illnesses, tuberculosis, syphilis, parasites, and fungi.

Inflammation of the urea involving the structures of the iris and/or ciliary body, including iritis, cyclitis, and iridocyclitis: Jane's ophthalmologist told her to use steroid eye drops as the initial treatment of anterior uveitis.

A nodular, chronic inflammation of the choroid, ciliary body, or iris: Granulomatous uveitis is usually caused by the presence of micro-organisms.

Granulomatous uveitis, or posterior uveitis, is characterized by the watering of the eyes which in turn causes impaired vision.

Intraocular inflammation: Phacoanaphylactic uveitis can occur after an extracapsular cataract extraction, which is believed to be an immune reaction to the patient's liberated lenticular proteins.

Uveitis (inflammation of part or all of the uvea, the posterior pigmented layer of the iris) secondary to hypermature cataract (cataract in which the lens cortex becomes liquid): Phacogenic uveitis is thought to be an autoimmune disorder with the production of autoantibodies causing a break in the lens capsule.

An extremely rare lens-induced uveitis: Phacotoxic uveitis, which is an inflammation of part or all of the uvea, is a low-grade reaction to the lens protein, and not a separate disease entity.

A severe, bilateral uveitis that starts as an inflammation of the uveal tract of one eye: Sympathetic uveitis can result from a puncture wound.

The injured eye is termed the "exciting eye". If the affected area is not removed within ten days of the accident that caused the wound, blindness will occur.