Blindness is the complete lack of form and visual light perception and is clinically defined as the inability to see no light in the visual field. Blindness is also defined as visual acuity of less than 20/400 (6/120 or a visual field loss to less than 10 degrees. As of 2013, there are 39 million people in the world who are blind.
Visual impairment is a dimension and category of vision loss requiring additional support. These impairments may appear as a result of disease, acute trauma, or congenital or degenerative conditions. A person with impaired vision experiences significant peripheral field defects. They also demonstrate symptoms consistent with a lowered contrast sensitivity.
The possible disorders that can lead to visual impairment or blindness are:
- Retinal Degeneration
- Corneal Disorders
- Diabetic Retinopathy
- Congenital Disorders
- Organic Brain Disorders
- Central Nervous System Disorders
The World Health Organization (WHO) has created classifications of visual impairment. Those classifications are as follows:
- 20/30 to 20/60 is a mild vision loss or almost normal vision.
- 20/70 to 20/160 is a moderate visual impairment.
- 20/200 to 20/400 is a severe visual impairment.
- 20/500 to 20/1,000 is near-total visual impairment
- No Light Perception is a total visual impairment.
A great number of individuals who experience visual impairment can be treated with optical aids. Low vision specialists can recommend the correct device and provide counseling in regard to how to deal with this visual impairment.
For those persons with visual impairment, there are books in braille, text-to-speech computer programs, e-book readers, and audio-books. Super large print is helpful and the e-book readers can be purchased with the ability to change font size. Computers also come with the ability to magnify the screen. Other technologies include the ability to use a closed-circuit television that magnifies paper and alters the color of paper and print.
In the lives of children, the use of phonics based reading materials has proven beneficial. The children are provided exciting, hands-on experiences wherein they are asked to imitate the sounds of consonants and vowels.
The World Health Organization has determined that 80% of all visual impairment can be prevented and cured. Over the last two decades the world as a whole and nations in particular have established increased programs and regulations to prevent visual impairment. Services directed toward the care of the eyes have increased and more programs are directed to primary and secondary health care systems. Educational campaigns have increased, government participation at national levels has improved, and the private sector has offered more solutions than ever before.
Global response by country include the following highlights:
- India has made funds available for eye care for the poorest of their population.
- Morocco created programs to control glaucoma.
- China invested one billion dollars in cataract surgeries.
- Brazil is providing eye care through their social security system.
- Australia is a forwarding thinking country using stem cell research and the creation of a bionic eye.