Uveitis is inflammation inside your eye. Inflammation usually happens when your immune system is fighting an infection. Uveitis can cause problems like pain, redness, and vision loss. Uveitis damages the part of the eye called the uvea — but it often affects other parts of the eye, too. Sometimes uveitis goes away quickly, but it can come back. And sometimes, it’s a chronic (long-term) condition. It can affect one eye or both eyes.