Diagnosis and management of functional visual deficits.

Patients with functional or nonorganic visual disturbances are often seen in general ophthalmology practice and then referred to neurology and/or neuro-ophthalmology. The diagnosis of functional vision loss requires comprehensive examinations and diagnostic testing to eliminate possible organic entities. Inconsistencies between examinations may be key to the functional/nonorganic nature. These cases represent some of the most time-consuming diagnoses that an ophthalmologist sees. These patients may be malingering or may have already seen multiple physicians. The more sophisticated patients may go online to learn about an entity that they are trying to mimic. Large amounts of time and money may be spent on diagnostic workups that are thought necessary to prove that there is nothing organic involved. Occasionally there are legal elements of the vision loss, such as minor trauma, in which case the history is key; the complaints tend to resolve when the legal issues are resolved. Another issue to consider is whether someone claiming to be blind is trying to qualify for workmen's compensation or disability.