• Blindness refers to a lack of vision. It may also
refer to a loss of vision that cannot be
corrected with glasses or contact lenses.
• Partial blindness means one has very limited
• Complete blindness means one cannot see
anything and do not see light. (Most people
who use the term "blindness" mean complete
Interesting to Know:
• Standard vision is measured as 20/20. A person is
considered "visually impaired" if he/she can see no
better than 20/70 with correction in his/her better
eye. This means he/she can see at 20 feet what
people with standard vision see at 70 feet.
• A person is also considered “legally blind” he/she
has limited peripheral vision and appears to be
seeing things as if looking through a tube or straw.
• A person is typically referred to as "totally blind" or
"black blind" if he/she has no visible sight.
What Causes Blindness?
• Medical conditions like Cataracts, Glaucoma,
• Age-related macular degeneration
• Eye injuries
• Severe periods of exhaustion or stress
• Pregnancy related issues
The type of partial vision loss may differ,
depending on the cause:
• With cataracts, vision may be cloudy or fuzzy,
and bright light may cause glare
• With diabetes, vision may be blurred, there
may be shadows or missing areas of vision,
and difficulty seeing at night
• With glaucoma, there may be tunnel vision
and missing areas of vision
• With macular degeneration, the side vision is
normal but the central vision is slowly lost
Other causes of vision loss include:
• Blocked blood vessels
• Complications of premature birth (retrolental
• Complications of eye surgery
• Lazy Eye
• Optic neuritis
• Retinitis pigmentosa
• Tumors such as retinoblastoma and optic glioma
• Disability does not mean that a person stops
living their life.
• Persons who are blind can and do live fully
• Just as we use certain equipment to make our
lives easier, certain aids and devices are used
by persons with blindness or low vision to
facilitate daily living.
• Many people with serious visual impairments can
travel independently, using a wide range of tools
• They rely on Orientation and mobility specialists
who are professionals specifically trained to teach
people with visual impairments how to travel
safely, confidently, and independently in the
home and the community.
• Becoming familiar with an environment or route
can make it much easier for a blind person to
• Tools such as the WHITE CANE with a red tip –
also the INTERNATIONAL SYMBOL of blindness
is used to improve mobility.
• A small number of people employ Guide Dogs to
assist in mobility.
• These dogs are trained to navigate around
various obstacles, and to indicate when it
becomes necessary to go up or down a step.
• TACTILE PAVING and AUDIBLE TRAFFIC
SIGNALS can make it easier and safer for
visually impaired pedestrians to cross streets.
READING AND MAGNIFICATION
• Most visually impaired people who are not totally
blind, read print, either of a regular size or enlarged by
magnification devices. Many also read LARGE–PRINT
which is easier for them to read without such devices.
A variety of MAGNIFYING GLASSES some handheld,
and some on desktops, can make reading easier for
• Others read BRAILLE or rely on TALKING
BOOKS and READERS or READING MACHINES
which convert printed text to speech
or Braille. They use computers with special
hardware such as SCANNERS
and REFRESHABLE BRAILLE DISPLAYS
and SCREEN READERS
BRAILLE IS a tactile writing system, traditionally written
with embossed paper. Braille-users can read computer
screens and other electronic supports thanks to
Refreshable Braille Displays.
WHAT IS BRAILLE ?
Blind people may use TALKING
as Thermometers Watches,
Clocks, Scales, Calculators
and Compasses. They may also
enlarge or mark dials on
devices such as ovens and
thermostats to make them
The JAWS software : Job Access With Speech
JAWS (Job Access With Speech) is a computer screen
reader program for Microsoft Windows that allows
people who are blind or Low Vision to read the screen
either with a text-to-speech output or by
a Refreshable Braille Display.
Low Vision Optical Devices
Low vision optical devices, such as magnifying reading
glasses, magnifiers, and small telescopes, are tools that
help those with vision loss maximize their remaining
Some Useful Tips when Communicating with
Persons who are Blind or have low vision
• Persons with visual impairment mainly experience
the world through hearing and touch. Thus it is
important to use auditory cues when communicating
with a person who is blind. For instance, when
meeting, introduce yourself and say something like
“shall we shake hands” instead of simply taking the
person’s hand and shaking it.
• Announce your arrival or departure so that you do
not take the person by surprise.
Some Basic Rules of Etiquette to Keep in Mind
• When offering assistance, ask the person directly
what you need to do. As a rule, allow the person to
take your arm. You should guide rather than propel
the person. Advise on steps or other obstacles as
• Point out to the direction of any object using the
analogy of a clock, such as, “the chair is to your three
What is Deaf-Blindness
such a condition
where the person
has little or no
useful sight and little
or no useful hearing.
How do persons who are Deaf-Blind
Deaf-Blind people communicate in many different ways
determined by the nature of their condition, the age of onset,
and what resources are available to them.
For example, someone who grew up deaf and experienced
vision loss later in life is likely to use a sign language (in a
visually modified or tactile form).
Others who grew up blind and
later became deaf are more
likely to use a tactile mode of
their spoken/written language.