Blindness (cont.)

Legal blindness is not a medical term. It is defined by lawmakers in nations or states in order to either limit allowable activities, such as driving, of individuals who are "legally blind" or to provide preferential governmental benefits to those people in the form of educational, service, or monetary assistance. Under the Aid to the Blind program in the Social Security Act passed in 1935, the United States Congress defined legal blindness as either central visual acuity of 20/200 or less in the better eye with corrective glasses or central visual acuity of more than 20/200 if there is a visual field defect in which the peripheral field is contracted to such an extent that the widest diameter of the visual field subtends an angular distance no greater than 20 degrees in the better eye.

It is estimated that approximately 700,000 people in the United States meet the legal definition of blindness.

Between 80%-90% of the blindness in the world is preventable through a combination of education and access to good medical care. Most traumatic causes of blindness can be prevented through instruction in eye protection. Nutritional causes of blindness are preventable through proper diet. Most cases of blindness from glaucoma are preventable through early detection and appropriate treatment. Visual impairment and blindness caused by infectious diseases have been greatly reduced through international public-health measures.

The majority of blindness from diabetic retinopathy is preventable through careful control of blood-sugar levels, exercise, avoidance of obesity and smoking, and emphasis on eating foods that do not increase the sugar load (complex, rather than simple carbohydrates). There has been an increase in the number of people who are blind or visually impaired from conditions that are a result of living longer. As the world's population achieves greater longevity, there will also be more blindness from other diseases such as macular degeneration. There are, however, new and evolving treatments for this disease and for diabetic retinopathy. Regular eye examinations may often uncover a potentially blinding illness which can then be treated before there is any visual loss.

Patients who have untreatable blindness require reorganization of their habits and reeducation to allow them to do everyday tasks in different ways. Visual aids, text-reading software, and Braille books are available, together with many simple and complex devices to provide functional improvement for the individual with blindness or low vision. In the United States and most other developed nations, financial assistance through various agencies can pay for the training and support necessary to allow a blind person to function.

John Milton and Helen Keller are well known for their accomplishments in life despite being blind. There are countless other unnamed individuals with blindness, however, who, despite significant visual handicaps, have had full lives and enriched the lives of those who have had contact with them.

Last Editorial Review: 3/10/2010 3:30:02 PM

Source: MedicineNet.com
http://www.medicinenet.com/blindness/article.htm