Monocular Diplopia: This double vision persists even when you cover one eye. It’s less common and typically indicates an issue within the eye itself, such as a detached retina or a cataract.

DEAR DR. ROACH: My husband woke up with double vision about three weeks ago. It appears that his left eye is turned inward and does not move with his right eye. He’s had a prescription for prednisone ...