The most common cause of protruding eyes is hyperthyroidism (overactivity of the thyroid gland), especially the form known as Graves' disease. (First Lady Barbara Bush had it.) One way to tell if an eye is bulging is to see whether there's any visible white part between the top of the iris and the upper eyelid, because normally there shouldn't be. (Some people inherit a tendency toward eyes that bulge, so if the appearance seems to run in a family, it probably isn't hyperthyroidism.) The person may not blink often and may seem to be staring at you. Because the condition develops slowly, it's sometimes first noticed in photos or by the occasional visitor rather than by someone who lives with the person every day.To see more details visit, health.msn.com/health-topics
