Definition of being "functionally blind"Social Security personnel, as well as some medical people who are unacquainted with blepharospasm, may have difficulty grasping the concept that people who cannot voluntarily open their eyes are just as sightless as those who are blind from actual disease of the visual system. This problem is even more confounding to the outsider because many people with blepharospasm experience some periods when their eyelids behave normally. When the eyes are open, the vision may be normal. But when the eyelids are forcibly closed because of involuntary, uncontrollable bilateral spasms of the orbicularis oculi muscles ("blepharospasm"), the patients can't see. They are "functionally blind" (sightless) until the eyelids open. The forced eyelid closure results from hyperexcitability of the nerves controlling the muscles of eyelid closure. Thus, an eye examination may show "normal vision," whereas a few minutes earlier or later, the patient's eyelids can be forcibly held shut by the spasms.Blepharospasm can be an isolated abnormality (benign essential blepharospasm), or it can co-exist with movement disorders involving the lower face and neck (segmental dystonia). In blepharospasm, whatever the cause, the person afflicted can be functionally blind and, if so, should be accorded the same disability considerations as individuals with primary abnormalities of the visual system.May 11, 2006 Disability index page BEBRF Blepharospasm Home Page |