Nerve Disease
Some cranial nerves link the eye muscles to the brain and transmit the impulses received from the eyes to the brain for interpretation. Several conditions can cause damage to these nerves and lead to the development of double vision.
Multiple sclerosis [3] is a progressive disease of the nervous system which results in the loss of myelin around nerve fibers. A chronic disease like this can affect the nerves responsible for coordinating vision and result in diplopia.
Another possible cause of double vision is Myasthenia gravis [4]. Myasthenia gravis is another debilitating nerve disease that triggers autoimmune responses against the neuromuscular junctions coordinating eye movements.
More common conditions such as diabetes can cause nerve damage in the eyes and trigger double vision.