Brown Syndrome is a rare eye disorder characterized by defects in eye movements. This disorder may be present at birth (congenital) or may occur as the result of another underlying disorder (acquired). Muscles control the movements of the eyes. Some of these muscles turn the eyeball up and down, move the eyeball from side to side, or enable the eyeball to rotate slightly in its socket. The superior oblique tendon sheath of the superior oblique muscle surrounds the eyeball. The symptoms of Brown Syndrome are caused by abnormalities of this tendon sheath including shortening, thickening, or inflammation. This results in the inability to move the affected eye upward.