An infection of the orbit, or boney eye socket, can lead to severe symptoms, one of which is double vision. Usually orbital infection spreads from adjacent sinuses, and sometimes from a skin or eyelid infection. Symptoms include pain, eyelid swelling and possibly a lump behind the eyelids that can be felt, eye and eyelid redness, discharge, blurred vision, eye displacement or protrusion, and double vision. The double vision comes from the infection preventing normal movement of the eye, and a misalignment may occur in certain positions of gaze. People with this condition are usually treated in the hospital with IV antibiotics.
Diabetics are subject to a particularly severe and destructive fungal orbital cellulitis.
A tumor of the orbit can cause similar symptoms, although usually with less pain, redness, and discharge. A CT scan or MRI is usually done in cases of orbital infection, tumor, or pseudotumor to help make the diagnosis and guide treatment. There are twelve cranial nerves, and they are often named by a number 1 through 12. These nerves pass under the brain to enter the orbit on each side, until they reach the muscles that they control. Damage to these nerves leads to paralysis of the muscles that they control.