The impairment of an extraocular muscle or the appearance of strabismus can cause double vision. The onset of this strabismus can occur at birth, or during a critical period in which the muscles can no longer maintain ocular alignment. Certain sudden onsets of neurological conditions can also directly affect the innervation and function of eye muscles. These ocular emergencies can be caused by cranial traumas, strokes, multiple sclerosis, tumors, diabetes or hypertension. The treatment for strabismus may include orthoptics, prisms in refractive lenses, or surgical procedures performed by an ophthalmologist. The treatment for the primary cause, however, is often more medical.
Accommodation can also be affected by a neurological disorder. This can lead to difficulties with focusing, maintaining clear vision, or alternating between different fixation points. Refractive correction or binocular exercises can help alleviate this problem.
Mild concussions can also affect the vision by reducing our ability to focus, to converge or to perform rapid eye movements. Glare is also an important concern that can cause discomfort when reading on screens. To help with this photophobia (light sensitivity), tinted lens or clips can be used.
Visual field defects are varied and can sometimes indicate damages to the visual areas of the brain. Using instruments that measure the visual field can help diagnose and follow the progression of these conditions.
It is important to remember that these issues are often considered medical emergencies; they require careful co-management with an ophthalmologist or a treating physician.