If a baby is born unable to see or has severe visual impairment, they are said to have congenital blindness. Several different conditions can cause congenital blindness, including certain diseases and genetic factors. The term "congenital" simply means that it is present from birth, and does not provide information on how long a child could be born blind. Blindness can also sometimes occur with other conditions, such as autism spectrum disorders and mental retardation.
There are many things that can cause a person to be born congenitally blind. One of them is a physical defect in the eyes or an abnormality in the brain. Some people are born blind due to infections their mothers developed while pregnant. For example, German measles, a viral disease, can affect developing babies and cause congenital blindness. Others may be born blind due to an inherited condition or due to an injury that occurs during childbirth.
One cause of congenital blindness is Leber congenital amaurosis (LCA), a rare degenerative disease in which the retinas do not function properly. Retinopathy of prematurity, a condition in which the retina of a baby born prematurely hasn't had time to develop properly, can cause blindness in severe cases. It's also possible for a baby to be born with congenital cataracts, which means the lens of the eye is cloudy, causing vision loss.
When children are congenitally blind, their learning and developmental needs are different. Barring any other conditions, they can learn and develop in the same way as other children, but they may need the help of teachers or special materials to help them do so without normal vision. There are many learning and development programs that emphasize the use of touch, hearing, and even taste and smell for learning.
Finally, the sense of touch plays a very important role in learning. Blind children and adults can use braille to read books, even though they cannot see them. This involves feeling little bumps or dots that represent letters and words, reading with your hands instead of your eyes.
A blind person's hearing can also play a critical role in their 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 instead of using braille. In fact, some of these devices make it possible for blind children to attend regular school if they wish.
The idea of being born blind or with significant vision problems can seem terrifying to sighted people. It can be hard to imagine how a blind person can accomplish daily tasks that most people take for granted, like going for a walk or running errands. One of the resources that a blind person can have is a guide dog. These dogs are specially trained to help visually impaired people move around and even cross streets safely.