About the Visually Impaired

People are said to have impaired vision when their sight is less than the average person’s field of vision. Visual impairments are usually more than just a need for glasses to read. Worldwide, around 314 million people are classified as being visually impaired, as statistics from the World Health Organization note. Of those, 45 million are totally blind. Childhood visual impairment accounts for more than 12 million cases of visual impairment.

Causes

Many different factors can contribute to visual impairment, including cataracts, glaucoma, macular degeneration, vitamin A deficiency, amblyopia, and diabetic retinopathy, according to the Teen’s Health website. Loss of eyesight usually occurs at a young age or at an older age, rarely during teen years. If visual impairment occurs during teen years, it is usually due to ocular or head injury. Congenital blindness in infants means that the baby is born with a visual impairment due to genetics or infection spread from the mother to the developing fetus.

Levels

The National Dissemination Center for Children with Disabilities describes visual impairment as having several different levels. Levels of visual impairment include moderate or severe visual impairment or total blindness. Partially sighted individuals have a moderate visual impairment but still have some eye function. Severe visual impairment is also known as low vision, meaning that the individual has trouble reading a document at normal reading distance even with glasses or contacts. Those with more severe visual impairment fall into the category of legal blindness, meaning that their vision is less than 20/200. Totally blind individuals have no vision at all.

Statistics

The World Health Organization compiles statistics about visual impairment in order to study them. Visual impairment more commonly affects older people. Females worldwide are more at risk for visual impairment than males. Visual impairment can be avoided in 85 percent of cases, but because 87 percent of people with visual impairment live in developing countries, the treatment comes either too late or not at all. However, the number of cases of blindness because of disease has decreased.

Testing

Those who suspect that they or their child has a visual impairment should go to an ophthalmologist. Ophthalmologists specialize in the diagnosis and treatment of eye diseases. Eye structure, reading distance, fluid pressure, and peripheral vision are all tested by the ophthalmologist to determine whether a visual impairment is present.

Treatment

If a person is determined to have a visual impairment, treatment can be prescribed in some instances. Some visual impairments can be corrected with glasses or contact lenses, while eye drops can help with other impairments. More serious impairments may require surgery to be corrected, as is the case with cataracts. In this instance, the clouded lens is removed and replaced with an artificial lens that restores vision.

For visual impairment that can’t be treated, such as blindness, other accommodations are made. Blind people have access to guide dogs, voice-recognition software, and Braille to make their lives easier. Scientists are also working on attempts to restore sight in the blind using gene therapy, according to the website Science Centric.