This is inflammation of the iris, the “colored” part of the eye. The iris is a muscle that controls the size of the pupil. When inflamed, the iris muscle can “spasm” and cause intense eye pain. Most people with an iritis complain of extreme sensitivity to light (photophobia). Iris inflammation can occur from many sources such as trauma or after intraocular surgery. Another cause is uveitis. Uveitis is a similar (but more encompassing) term used to describe internal ocular inflammation, usually from pro-inflammatory systemic problems like sarcoidosis, rheumatoid arthritis, inflammatory bowel disease, and infection. Treatment for iritis involves topical steroids to “cool” the eye down. Cycloplegia dilating drops can help with iris pain by “paralyzing” the iris muscle so that it stops “spasming.” Dilation drops are also helpful because they keep the pupil dilated and help avoid the formation of iris synechiae (this is when the iris inflammation causes it to ‘stick’ to nearby structures like the lens underneath).