Are there any underlying illnesses related to swelling in the iris of the eye?

Rare: Even when there is inflammation inside the eye (uveitis) rarely does the iris swell. Uveitis, also called iritis, can be related to intestinal and rheumatic conditions as underlying illness. When that occurs the iris can get stuck to the lens inside the eye and cause problems which the ophthalmologist need to treat, - sometimes on an emergency basis.