What causes diplopia, or double vision?
Opening your eyes and seeing a single, clear image is something you probably take for granted. But that seemingly automatic process depends on the orchestration of multiple areas of the vision system. They all need to work together seamlessly: • The cornea is the clear outermost disc covering the eye. It allows in focused light. • The lens is behind the pupil. It focuses light onto the retina. • Muscles of the eye — extraocular muscles — perform the eye’s precise movements. • Nerves carry visual information from the eyes to the brain. • The brain is where several areas process visual information from the eyes. Problems with any part of the vision system can lead to diplopia. It makes sense to consider the causes of diplopia according to the part of the visual system that has the problem. Cornea problems. Problems with the cornea often cause double vision in one eye only. Covering the affected eye makes the diplopia go away. The damaged surface of the eye distorts incoming light, caus
