You definitely need to see your doctor
as soon as possible. The concern here is that you could have uveitis, which is an inflammation of some of the structures in the eye. If untreated, uveitis can cause damage to the eye and can lead to permanent vision loss.
Uveitis can indeed be associated with stiffness and joint pain
. There are a number of autoimmune joint conditions which have, as one of their associated complications, uveitis. So this is the key thing to rule out. You should see your eye doctor
or go to an emergency room for evaluation. In addition to the eye inflammation and getting that under control, you will also need work up for the joint inflammation, but that is less urgent and can happen later.
Of course there are many other causes of eye inflammation, including simple conjunctivitis, scratches to the cornea, and other things that are less serious. Your eye doctor will be able to take a close look at your eye with a special microscope and help sort out whether you have uveitis or something less serious. Based on what they find, they will also decide which medications you need to be on to reduce the inflammation.