Kinds of Visual Impairments
Congenital Blindness
Some people are visually impaired at birth. Congenital blindness can be caused by a number of things — it can be caused by an infection (like German measles) that's transmitted from the mother to the developing fetus during pregnancy.Others may be born blind because of an inherited condition or due to an injury that happens during childbirth.
Coping:
When children have congenital blindness, their learning and development needs are a bit different. They can learn and develop in much the same way as other children. They may need the help of special teachers or materials to help them do so without normal sight. There are many learning and developmental programs that are based on using touch, hearing, and even taste and smell to learn.
Blind children and adults can use braille to read books, even though they cannot see them. This involves feeling small bumps or dots that represent letters and words, reading with the hands instead of the eyes.
A blind person’s hearing can also play a critical role in his ability to learn and read. There are devices designed to read information on a written page, allowing blind people to listen to books and written materials rather than using braille. In fact, some of these devices make it possible for blind children to attend regular school if they wish.
One of the resources a blind person may have is a guide dog. These dogs are specially trained to help visually impaired people move about and even cross streets safely.
Amblyopia
This is reduced vision in an eye because lack of use of that eye in early childhood. For example, one eye might focus better than the other. The brain may then turn off or suppress images from the weaker eye and vision from that eye then stops developing normally. This is also known as a "lazy eye." Misaligned or crossed eyes can cause Amblyopia.The condition affects approximately 2 to 3 out of every 100 children. It occurs when the vision in one of the eyes is reduced because the eye and the brain are not working together properly. The eye itself looks normal, but it is not being used normally because the brain is favoring the other eye. This condition is also sometimes called lazy eye.
Causes:
Sometimes amblyopia is caused when one eye is more nearsighted, farsighted, or astigmatic than the other eye. Occasionally, amblyopia is caused by other eye conditions such as cataract. It can also be caused due to an imbalance in the positioning of the two eyes Amblyopia is caused by other eye conditions such as cataract.
Glaucoma
Glaucoma is often called "the sneak thief of sight." When pressure inside eye increases this problem can happen. The Vision can be impaired due to pressure and optic nerve can be damaged. Glaucoma is mostly seen in older adults.Glaucoma is the leading cause of blindness in the world.
The major risk factors include:
Age over 45 years
Family history of glaucoma
Black racial ancestry
Diabetes
History of elevated intraocular pressure
Nearsightedness (high degree of myopia), which is the inability to see distant objects clearly
History of injury to the eye
Use of cortisone (steroids), either in the eye or systemically (orally or injected)
Farsightedness
Treatment:
Although nerve damage and visual loss from glaucoma cannot usually be reversed, glaucoma is a disease that can be controlled. That is, treatment can make the intraocular pressure normal and, therefore, prevent or retard further nerve damage and visual loss. Treatment may involve the use of eye drops, pills (rarely), laser, or surgery.
Macular degeneration
It is a slow and progressive deterioration of the most sensitive region of the retina. There is a loss of central vision. One is not able to see fine details. This problem is often age related. Risk for age related macular degeration can increase if excessive exposure to sunlight is there. Symptoms may include increased difficulty reading or watching TV, or distorted vision in which straight lines appear wavy or objects look larger or smaller than normal.
Trachoma
It occurs due to a very contagious micro organism. Because of over crowding and insanitary conditions this infection can be caused. So it is more common in areas of abject poverty. It causes inflammation in the eye. It's often found in poor rural countries that have overcrowded living conditions and limited access to water and sanitation. Such blindness has been eliminated from U.S.A.
