Double vision, or binocular diplopia, results when the two eyes are misaligned and aim at different targets. In these cases, two non-matching images are being sent to the brain and double vision results. Permanent double vision can be due to a structural defect in the eye's optical system. Temporary double vision typically results from a traumatic event or other condition, says AllAboutVision.com.
Alcohol
Alcohol is a depressant. According to Dr. Bruce Martin, a physiology professor at Indiana University, it slows down the brain so that the brain of an intoxicated person is not able to control the eye movements as effectively as that of a person who has not consumed alcohol. This results in temporary double vision. A person who is under the influence of alcohol is not able to follow moving objects effectively. Many drugs cause double vision, as well.
Migraine Headaches
Typical migraines symptoms include headaches and nausea, but problems with vision are also frequent among migraine patients. Besides double vision, patient may see halos, spots of light or zigzag patterns, says MedlinePlus. Such symptoms are most common prior to the beginning of the headache. Some migraines, called ophthalmic migraines, cause symptoms in vision but have no headache.
Head Trauma or Stroke
Double vision is a common symptom of head trauma that has resulted from an accident. Patients may also have lost consciousness, feel nauseated, suffer from seizures and be incoherent.
Double vision following a stroke can be constant or intermittent. The patient may see normally in the straight ahead location, but begins to see double if he looks to the side. Other problems in vision are also common. These include loss of visual field or loss of the ability to see to the side. Some patients also suffer from light sensitivity. Other stroke symptoms include headaches, paralysis of a face, arm or leg, especially on one side, and problems in producing or understanding language.
Brain Tumor
A growing tumor in the brain can damage the nerves that connect to the eyes or it can cause damage to the visual cortex, says MayoClinic.com. This can lead to many problems in vision including reduced field of vision or double vision. Other symptoms of brain tumors include headache, nausea, seizures and changes in personality. The symptoms caused by brain tumors tend to become more intense and frequent when the tumor is growing in size.
