Wikipedia has more on Diplophobia.
Diplophobia (from diplos, meaning double) is the fear of double vision. This fear can occur when someone has experienced it from the past or when elders tell them they will have double vision when they read in the dark. People may have this fear due to strong genetic influence, others have experienced it through trauma. People whose careers rely on vision, often are worried about their eyesight and are more alert regarding the disease. Fear of side effects from surgery or other types of illnesses can be a potent trigger for diplophobia. People who work at graveyard shifts and those who are insomniacs struggle with double vision as their body may strain from staying up late. Alcohol and drugs may also cause double vision. People with addictions may be more apt to struggle with diplophobia, as their compulsions make it difficult to give up the causes of their eye problems.
Double vision can be a red flag that something is very wrong such as stroke, aneurysm or a brain tumor since these medical issues can be life-threatening. Someone who has a medical history of any of these problems may develop phobia because they see it as a potential cause of sudden death.
People who fear double vision may suffer panic attacks when they feel a sudden sense of doom. They may also feel nauseous and upset when faced with double vision.
The best treatment for this phobia is medical care or psychotherapy. If there is some legitimate health concern that is triggering this disorder, proper screening by a doctor is vital. If the problem is psychological, it should be addressed by a trained professional who can get at the root of the phobia you can also heal the phobia more facts are bellow.
for some reason this phobia can be cured thanks to drugs and cursing on god