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 inherited or caused by an infection (like German measles) that's transmitted from the mother to the developing fetus during pregnancy.
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
Glaucoma
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.
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.
