Information Guide About Blindness and Visual Impairments
Blindness is a medical condition in which an individual lacks visual perception abilities because of neurological or physical problems. People suffering from blindness are classified as having total blindness, blindness, legal blindness, or low vision. An individual with total blindness has no ability to perceive light or form. An individual with blindness has the ability to tell light from dark but cant perceive anything else visually. An individual with legal blindness may be able to perceive more than an individual with blindness or total blindness, but his/her limitations are severe enough to warrant special assistance. To be legally blind, an individuals vision must typically be worse than 20/200. An individual with low vision has visual acuity worse than 20/60 but better than 20/200. As of 2002, 161 million people in the world were experiencing visual impairment. This amounts to approximately 2.6 percent of the population. 124 million of these people suffer from low vision and 37 million are blind. The most frequent causes of blindness are cataracts, refractive errors, macular degeneration, and glaucoma.
Blindness Information - This article from Kids Health talks about sight and vision and some of the many causes of blindness.
Living with Low Vision - The American Foundation for the Blind provides this resourceful page on information on blindness, including a glossary of terms.
Blindness - Learn more about the various degrees of blindness and how they are classified on this page from the New York Times.
Vision Impairment and Blindness - Read a definition of low vision on this page from Medline Plus.
Diseases
Cataracts
A cataract is a condition that clouds the eye's lens. This clouding impedes the passage of light through the eye and may cause blindness. Though most cases of cataracts result from the aging process, some babies may be born with them. Cataracts may also be caused by inflammation, eye injuries, or diseases that affect the eye. Cataracts can be surgically removed, but surgery isn't always a cure for the low vision caused by the condition.
Cataracts More information about cataracts, as well barriers to cataract care.
Hope through Research Read about the strides scientists are making in combating cataracts.
Glaucoma
Glaucoma is a disease that causes structural changes to the eye that can lead to functional problems. There are several forms of glaucoma including primary open angle glaucoma and angle closure glaucoma. It is estimated that approximately 4.5 million people in the world suffer blindness because of glaucoma. Most cases of glaucoma result from genetic predisposition and age.
Glaucoma A brief overview of the disease, as well as links to more information.
Glaucoma Research New and future methods of treating and preventing glaucoma.
Age-Related Macular Degeneration
Age-related macular degeneration is a condition that causes an individual to lose his central field of vision. This condition usually affects individuals over age 50. The condition occurs when degenerative lesions develop on the central retina. Risk factors for age-related macular degeneration include circulatory insufficiency, age, genetics, tobacco use, exposure to ultraviolet rays, and degree of pigmentation.
What is AMD? More information about a disease affecting more than 15 million people in the United States alone.
Age-Related Macular Degeneration This site, provided by the American Academy of Ophthalmology, gives information on who is at risk, how AMD is diagnosed, and the differences between wet and dry AMD.
Corneal Opacity
Corneal opacities result from inflammatory eye diseases that cause scars to develop on the cornea, which is a clear membrane covering the eye. The scarring eventually leads to blindness. This cause of blindness is more prevalent in underdeveloped countries. The only treatment for corneal opacity is surgery.
Corneal Opacity A site detailing the definition, causes, and risk factors of corneal opacity.
Basics of Corneal Opacification More information about this disease, as well as a section detailing the resources from which the information came.
Diabetic Retinopathy
Diabetic retinopathy occurs when lesions form on the retina due to complications from diabetes mellitus. The lesions cause thickening of the central portion of the retina, which reduces vision. Diabetic retinopathy is responsible for approximately 5 percent of the blindness in the world. The best prevention for this condition is proper treatment of diabetes mellitus.
Diabetic Retinopathy The American Optometric Association gives information about the causes and treatment of diabetic retinopathy, as well as how it is diagnosed.
Treatment Options for Diabetic Retinopathy While the only for diabetic retinopathy if it progresses to macular edema is surgery, but the methods of that surgery are more refined today than ever.
Childhood Blindness
Childhood blindness refers to loss of vision acquired during childhood. Several different diseases may cause childhood blindness. The major causes of this condition vary by region and are usually determined by the availability of healthcare. In high-income countries, the most common causes of childhood blindness are lesions on the optic nerve or higher visual pathways. In countries with lower incomes, vitamin deficiency, scarring from measles, rubella, and birth defects are common causes of childhood blindness.
Childhood Blindness The global impact of childhood blindness, and what one organization is doing to help those in need because of it.
Causes of Childhood Blindness While there are many causes of childhood blindness, there are some common ones that can be done away with, provided there is a concerted effort.
Trachoma
Trachoma is an infectious disease caused by chlamydia trachomatis. The disease is spread from person to person by contact with infected eye discharge or eye-seeking flies. After repeated instances of infection, the eyelid becomes scarred and turns inward. The eyelashes then rub on the eyeball and cause scars to form on the cornea. This cause of blindness is more prevalent in areas with poor hygiene.
Trachoma A site detailing how trachoma is detected and its treatment.
Trachoma Control Program Controlling trachoma is partially about improving living conditions in some parts of the world. Learn what the Carter Center is doing to accomplish just that.
Onchocerciasis
Onchocerciasis is a disease caused by a parasite known as onchocerca volvulus. This parasite is carried and transmitted by insects. The disease causes eye lesions, which lead to bleeding, inflammation, and blindness. This cause of blindness is most prevalent in African countries.
Onchocerciasis Basic information about the disease, as well as public initiatives that have been undertaken to reduce its prevalence.
What is River Blindness? There are over 30 million people worldwide afflicted with River Blindness. This site details the treatments and what can be done to prevent it.
Guide Dogs
A guide dog is a dog that is trained to assist a blind individual with navigation. Guide dogs have been in existence since the middle of the 16th century. However, the first training schools for guide dogs were opened during World War I to assist blind veterans returning from combat. The first school in the United States was established in 1929 in Nashville, TN. The first guide dogs were German Shepherds, but many other breeds are currently in use. The most common breeds used today are German Shepherds, Labradors, and Golden Retrievers. The Americans with Disabilities Act requires all businesses, organizations, and government agencies to allow guide dogs access to their facilities.
GuideDogs.com A site dedicated to matching the blind with guide dogs to increase mobility and independence.
Southeastern Guide Dogs Applying for a guide dog and volunteering to train them is easy through this site.
International Association of Assistance Dogs Partners An organization which represents consumer interests in the guide dog field.
Service Dog Trainers A site which provides the contact information of organizations that train service dogs.
Service Animals and Companion Dogs A resource guide for more information on guide dogs.
About Guide Dogs Information on the dogs that allow the blind their rightful independence.
The Seeing Eye Another organization dedicated to providing the blind with guide dogs.
Fidelco Guide Dog Foundation The guide dogs from this organization have even helped veterans return to their important work.
Additional Resources
Foundation Fighting Blindness An organization with a mission of driving research that will reduce the instances of blindness worldwide.
Blindness Resource Center This site, maintained by the New York Institute for Special Education provides dozens of resources for information about blindness.
Blindness in the Workplace Answering any questions you may have about accommodations which must be made under the Americans with Disabilities Act.
Journal of Blindness Innovation and Research A chronicle of the amazing work being done in current blindness research.
Prevention of Blindness Society This society is the largest of its kind in the United States, doing excellent work for the past 75 years.
Glaucoma Service Foundation to Prevent Blindness This foundations mission is to support and enhance the lives of people with glaucoma.
Blindness Information An overview of blindness and vision loss, as well as some of the treatments.
Leading Causes of Blindness Basic information about the most prevalent blindness-causing diseases in the world.
History of Blindness How people and organizations have historically helped (or not helped) the blind.
National Consortium on Deaf-Blindness An organization dedicated to helping people who are both deaf and blind achieve the maximum amount of independence.
Basic Blindness Information A useful page with not only information on blindness, but how sighted people can comfortably and effectively interact with the blind.
