Have you ever put on a blindfold and pretended that you
couldn't see? You probably bumped into things and got confused
about which way you were going. But if you had to, you could get
adjusted and learn to live without your sight. Lots of people have
done just that. They have found ways to learn, play, and work, even
though they have trouble seeing or can't see at all.
How Seeing Happens
Your eyes and your brain work together to see. The eye is made
up of many different parts like the cornea, iris, lens, and retina.
These parts all work together to focus on light and images. Your
eyes then use special nerves to send what you see to your brain, so
your brain can process and recognize what you're seeing. In
eyes that work correctly, this process happens almost
When this doesn't work the way it should, a person may be
visually impaired, or blind. The problem may affect one eye or both
eyes. When you think of being blind, you might imagine total
darkness. But some people who are blind can still see a little
light or shadows. They just can't see things clearly. People
who have some sight, but still need a lot of help, are sometimes
called "legally blind."
What Causes Blindness?
Vision problems can develop before a baby is born. Sometimes,
parts of the eyes don't form the way they should. A kid's
eyes might look fine, but the brain has trouble processing the
information they send. The optic nerve sends pictures to the brain,
so if the nerve doesn't form correctly, the baby's brain
won't receive the messages needed for sight. Blindness can be
genetic (say: juh-
-tik) or inherited (say: in-
-ut-ed), which means that this problem gets passed down to a kid
from parents through genes.
Blindness also can be caused by an accident, if something hurts
the eye. That's why it's so important to protect your eyes
when you play certain sports, such as hockey.
Some illnesses, such as
, can damage a person's vision over time. Other eye diseases,
-tuh-rakts), can cause vision problems or blindness, but they
usually affect older people.
What Does the Doctor Do?
If a kid has serious trouble with vision, he or she might see an
-luh-jist), a doctor who specializes in eye problems. Even babies
might see an ophthalmologist if their parents think they might be
having trouble seeing.
At the doctor visit, the doctor will talk with the parents and
the kid (if the kid is old enough to describe what's going on).
A doctor might use an eye chart to find out how well the kid can
see. You've probably seen these charts that contain letters of
different sizes. It's a way of testing how well a person can
see. Someone with really good vision would be able to read certain
letters from 20 feet (6 meters) away.
Eyesight this good is called 20/20 vision, although some people
can see even better than that. The numbers change depending on how
clearly a person can see. The larger or closer something needs to
be in order for it to be seen, the worse a person's vision is.
Many times, glasses or contact lenses are all that's needed
to help kids see better. But if glasses and contact lenses
can't make the person's vision any better - and the person
needs to get really close to something to see it - he or she may be
considered blind. For instance, someone with good vision might be
able to see an object from 200 feet (61 meters) away, but someone
is considered blind if he or she needs to be 20 feet (6 meters)
away to see the same object.
Babies and little kids won't be able to use the eye chart,
but doctors can check their vision by doing special vision tests or
something as simple as putting a toy in front of the child to see
if he or she can focus on it.
The ophthalmologist also will examine the kid's eyes using
special medication and lighting that allows him or her to see into
the eyeballs. The ophthalmologist will look at each part of the eye
to check for problems, such as a cataract (cloudiness of the
eye's lens). Once the doctor knows what's causing the
vision problem, he or she can begin planning how to treat it.
In some cases, an operation can help improve a kid's vision.
For example, if a kid has a cataract, doctors may do surgery to
Is Learning Different?
If a baby is blind, he or she can still learn and develop
normally. But the baby's parents will need the help of
specialists who know how to help blind children. It's often a
great idea for the child to attend special learning programs
designed just for little kids who have trouble seeing. These
programs would make the most of the senses that the kid does have,
Touch comes in handy when a child is older and wants to read
books. Kids who are visually impaired can learn to read by using a
special system called braille. Braille is a way of expressing
letters, words, and thoughts. To read braille, a person feels a
series of little bumps that are associated with letters in the
alphabet. For instance, "A" is represented as one bump.
Computer programs and other devices that can "see" turn
the words on a page into braille.
Hearing is another important sense if a kid has vision problems.
Some devices can read out loud what's written on a page. With
special equipment, a visually impaired kid can read almost
anything. These kinds of technologies can be helpful in learning.
Kids who are blind might attend a special school, or they might
attend regular classes, aided by special devices and
Kids who have vision problems will get help from their parents,
doctors, and teachers. When they are older, some of them may get a
hand - or should we say a paw? - from a guide dog. These helper
dogs are trained to be a blind person's eyes. That means the
dog learns to be very alert to surroundings so he or she can be a
good guide for the person.
Not only are these dogs great friends, they give blind people
independence, so they can accomplish what they want to
Many blind people have gone on to do amazing things in many
different fields, including music, the arts, and even sports.
Serious vision problems didn't stop runner Marla Runyan. She
was the first legally blind person to ever qualify for the
Updated and reviewed by:
Robert W. Hered, MD
Date reviewed: November 2007
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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