your symptom is very nonspecific and could be a result of multiple processes ranging from direct pressure having been applied to the eyeball by your hand/arm etc. to a tumor in the back of the eye (very very rare and unlikely). You need to be evaluated by an ophthalmologist who can review your full health, list of medications, and possible risk factors for serious problems and perform a full eye exam to ensure everything is OK. You could find one at www. aao.org or ask your primary care doctor to refer you to an eye MD.