Grave's ophthalmopathy occurs when cells from the immune system attack the muscles and other tissues around the eyes leading to inflammation and a build-up in tissue and fat behind the eye socket, causing the eyeballs to swell up and be 'pushed out'. In rare cases, inflammation is severe to compress the optic nerve that leads to the eye, causing vision loss. Symptoms include:dry, irritated eyes, puffy eyelids, double vision, light sensitivity, pressure or pain in the eyes and trouble moving the eyes.
Attribution: Straight Talk Foundation