especially astigmatism, can also produce this symptom. Temporary Temporary binocular diplopia can be caused by alcohol intoxication or head injuries, such as concussion (if temporary double vision does not resolve quickly, one should see an optometrist or ophthalmologist immediately). It can also be a side effect of benzodiazepines or opioids, particularly if used in larger doses for recreation, the antiepileptic drugs phenytoin and zonisamide, and the anticonvulsant drug lamotrigine, as well as the hypnotic drug zolpidem and the dissociative drugs ketamine and dextromethorphan. Temporary diplopia can also be caused by tired or strained eye muscles. If diplopia appears with other symptoms such as fatigue and acute or chronic pain, the patient should see an ophthalmologist immediately. Voluntary Some people are able to consciously uncouple their eyes, either by overfocusing closely (i.e., going cross-eyed) or unfocusing. Also, while looking at one object behind another object, the foremost object's image is doubled (for example, placing one's finger in front of one's face while reading text on a computer monitor). In this sense, double vision is neither dangerous nor harmful, and may even be enjoyable. It makes viewing stereograms possible. Monocular diplopia may be induced in many individuals, even those with normal eyesight, with simple defocusing experiments involving fine, high-contrast lines. Treatment The appropriate treatment for binocular diplopia depends upon the cause of the condition producing the symptoms. Efforts must first be made to identify and treat the underlying cause of the problem. Treatment options include eye exercises, wearing an eye patch on alternative eyes, prism correction, and in more extreme situations, surgery or botulinum toxin. If your provider diagnoses swelling or inflammation of, or around the nerve, medicines called corticosteroids may be used. Sometimes, the condition disappears without treatment. If you have diabetes, you'll be advised to keep tight control of your blood sugar level. The provider may prescribe an eye patch to relieve the double vision. The patch can be removed after the nerve heals. Surgery or special glasses (prisms) may be advised if there is no recovery in 6 to 12 months. If diplopia turns out to be intractable, it can be managed as last resort by obscuring part of the patient's field of view. This approach is outlined in the article on diplopia occurring in association with a condition called horror fusionis. See also Binocular vision Monocular rivalry Orthoptics References Further reading External links Deciphering Diplopia Visual disturbances and