Many people with severe visual impairments can travel independently using a variety of tools and techniques. Orientation and Mobility Specialists are professionals specially trained to teach people with visual impairments how to travel safely, confidently and independently at home and in the community. These professionals can also help blind people train to travel on specific routes they use frequently, such as driving home to a supermarket. Becoming familiar with an environment or route can make it easier for a blind person to navigate successfully. The Dutch painter and printmaker Rembrandt often depicted scenes from the Apocryphal Book of Tobias, which tells the story of a blind patriarch who is healed by his son Tobias with the help of the archangel Raphael.  There are several ways to define blindness. Many people think of blindness as the inability to see at all, or at best distinguish light from darkness. The National Federation of the Blind takes a much broader view. We encourage people to consider themselves blind if their vision is poor enough – even with corrective lenses – that they need to use alternative methods to perform any activity that people with normal vision would perform with their eyes. Eye trauma or injury and genetic diseases, such as Usher syndrome, can also lead to legal blindness. Vision is most often described as a measure of visual acuity, or the best a person can see. 20/20 is considered normal vision; While 20/50 prohibits driving in Texas without special aids, 20/70 is called visual impairment, and if a person sees 20/200 or worse in their best eye with the best possible correction on that eye, that person is considered “legally blind.” A person can see with uncorrectable 20/200 vision, but often too little is recognized as very useful.
To be legally blind, you must meet one of two criteria: visual acuity (visual acuity) and field of vision (the full range of what you can see without moving your eyes). An ophthalmologist will measure visual acuity and visual field to determine if a person is legally blind. In 1987, an estimated 598,000 people in the United States met the legal definition of blindness.  Of these, 58% were over the age of 65.  In 1994-1995, 1.3 million Americans reported being legally blind.  The legal definition of “legally blind” is that the central visual acuity of the better eye must be 20/200 or less with the best possible correction, or the field of vision must be twenty degrees or less. Each year, the American Printing House for the Blind (APH) surveys each state to obtain data on the number of legally blind children (up to twenty-one years old) enrolled in elementary and secondary schools in the United States who are eligible for free reading in Braille, large print, or audio. This is used to develop a “quota” of federal funds spent in each state on hardware in any alternative format. The U.S.
Bureau of the Census`s question on “significant vision loss” includes both complete or near-complete blindness and “vision problems, even when wearing glasses or contact lenses.” People with significantly reduced visual acuity can benefit from training provided by people trained in the provision of assistive technologies. Rehabilitation professionals for the visually impaired, some of whom are affiliated with a blind agency, can offer advice on lighting and contrast to maximize remaining vision. These professionals also have access to non-visual aids and can teach patients how to use them. Cataracts are the graying or clouding of the lens that can be caused in children by intrauterine infections, metabolic disorders and genetically transmissible syndromes.  Cataracts are the leading cause of blindness in children and adults, with a prevalence doubling every ten years after the age of 40.  As a result, cataracts are now more common in adults than in children.  That is, people are more likely to develop cataracts as they age. Nevertheless, cataracts tend to have a greater financial and emotional impact on children, as they require expensive diagnosis, long-term rehabilitation, and visual support.  According to the Saudi Journal for Health Sciences, patients sometimes experience irreversible amblyopia after pediatric cataract surgery because cataracts prevented normal maturation of vision before surgery.  Despite major advances in treatment, cataracts remain a global problem in both economically developed and developing countries.
 Given the different outcomes and uneven access to cataract surgery, the best way to reduce the risk of developing cataracts is to avoid smoking and exposure to the sun (i.e., UV-B rays).  Part 1 of the U.S. definition of right blindness states the following about visual acuity: H. G. Wells` story “The Country of the Blind” examines what would happen if a sighted man were trapped in a land of the blind in order to highlight society`s attitude toward the blind by reversing the situation. If you learn that you are legally blind, organizations like the American Foundation for the Blind can help. They have programs to help you cope with the physical and emotional effects of vision loss. Among newly blind working-age adults in England and Wales, the most common causes in 2010 were: The terms may also be used by health insurers to determine benefits and as part of vision tests required by State Motor Vehicle Departments (DMVs) when determining driver`s license eligibility. For safety reasons, people who are legally blind or visually impaired are generally not entitled to a driver`s licence.