An Overview of Visual Impairment
Objectives:
At the end of the session, you will be able to:
· Describe meaning of legal blindness
· Distinguish between myths and facts of visual impairment
· Explain types of visual impairment
· Discuss the implications of visual impairment
We are going to discuss a brief overview of visual impairment to understand the
following:
· What is visual impairment?
· What are the different types of visual impairment?
· How do we identify a child who may be at-risk for visual impairment in a classroom?
We will begin with a story which may be heard before. There were some blind people
who were asked to describe an elephant.One blind person, who touched the tail of the
elephant, described the elephant as a rope.Another blind person, who touched the leg of
the elephant, thought it was a trunk of a tree.While another person who touched the ear
of the elephant, thought it was a fan. Basically we are trying to say that the blind people
describe the world around them on the basis of what they feel with their fingers. So, it is
ofparamount importance for us to bring the world to their hand.
Meaning of Total and Legal Blindness:
Let’s look at different types of visual impairment.Generally, people think that anybody
who is visually impaired is totally blind, but that is not the case.Total blindness is one
type of visual impairment when there is no sight and no perception of light.There are
people who have a visual acuity of 20/200 or less than that and a visual field of 20
degrees or less, they are called legally blind.Legal blindness is a commonly used term for
visual impaired person. Let’s understand the meaning of legal blindness: A person is
called legally blind if his visual acuity is less than 20/200 in better eye and his field of
vision is less than 20 degrees.
, What dowe mean by 20/200 visual acuity?
Visual acuity is basically with what clarity a person can see, a normal sighted person
what s/he can see at a distance of 200 feet, a visually impaired person can see the same
thing at a distance of 20 feet that means s/he has to come so much closer to the object
to see it.
A visual field is what a person can see from right to left which is 180 degree for a sighted
person, but for a legally blind person it is less than 20 degrees after correction in the
better eye. A person is called legally blind because if s/he falls in that category then s/he
is entitled for all the legal concessions meant for the visually impaired.
Majority of visually impaired people come in the category of low vision persons.
According to WHO a low vision person is one who has a visual acuity less than 20/60 to
20/200 and s/he has a visual field of more than 10 degrees up to 40 degrees in the
better eye.
Another definition of low vision is a low vision person is one who has some vision and his
visual efficiency can be improved with the help of optical aids, non-optical aids and
environmental modifications. This definition has educational implications. Its more
important for teachers to focus on what kind of optical aids for example magnifiers,
lenses, specially designed glasses can be used which will help the child to see better,
non-optical aids for example large print books which can again help the child to be
included in a regular class. Environmental modifications fare, for example: you give him
good contrast, you make him sit in a place where there is better lighting, with these
modifications a child’s visual functioning can be definitely improved.
Myths and Facts of Visual Impairment:
It is interesting to know that how many myths are associated with visual impairment, for
example: people believe that if a person is low vision s/he should not use his/her vision
at all on the contrary a person who has limited vision what we call the residual vision
should be encouraged to use it as much as possible. Many a times we observe children
bringing their books too close to their eyes and we dissuade them from doing that
thinking that they will lose whatever vision they have again but the fact is that they may
Objectives:
At the end of the session, you will be able to:
· Describe meaning of legal blindness
· Distinguish between myths and facts of visual impairment
· Explain types of visual impairment
· Discuss the implications of visual impairment
We are going to discuss a brief overview of visual impairment to understand the
following:
· What is visual impairment?
· What are the different types of visual impairment?
· How do we identify a child who may be at-risk for visual impairment in a classroom?
We will begin with a story which may be heard before. There were some blind people
who were asked to describe an elephant.One blind person, who touched the tail of the
elephant, described the elephant as a rope.Another blind person, who touched the leg of
the elephant, thought it was a trunk of a tree.While another person who touched the ear
of the elephant, thought it was a fan. Basically we are trying to say that the blind people
describe the world around them on the basis of what they feel with their fingers. So, it is
ofparamount importance for us to bring the world to their hand.
Meaning of Total and Legal Blindness:
Let’s look at different types of visual impairment.Generally, people think that anybody
who is visually impaired is totally blind, but that is not the case.Total blindness is one
type of visual impairment when there is no sight and no perception of light.There are
people who have a visual acuity of 20/200 or less than that and a visual field of 20
degrees or less, they are called legally blind.Legal blindness is a commonly used term for
visual impaired person. Let’s understand the meaning of legal blindness: A person is
called legally blind if his visual acuity is less than 20/200 in better eye and his field of
vision is less than 20 degrees.
, What dowe mean by 20/200 visual acuity?
Visual acuity is basically with what clarity a person can see, a normal sighted person
what s/he can see at a distance of 200 feet, a visually impaired person can see the same
thing at a distance of 20 feet that means s/he has to come so much closer to the object
to see it.
A visual field is what a person can see from right to left which is 180 degree for a sighted
person, but for a legally blind person it is less than 20 degrees after correction in the
better eye. A person is called legally blind because if s/he falls in that category then s/he
is entitled for all the legal concessions meant for the visually impaired.
Majority of visually impaired people come in the category of low vision persons.
According to WHO a low vision person is one who has a visual acuity less than 20/60 to
20/200 and s/he has a visual field of more than 10 degrees up to 40 degrees in the
better eye.
Another definition of low vision is a low vision person is one who has some vision and his
visual efficiency can be improved with the help of optical aids, non-optical aids and
environmental modifications. This definition has educational implications. Its more
important for teachers to focus on what kind of optical aids for example magnifiers,
lenses, specially designed glasses can be used which will help the child to see better,
non-optical aids for example large print books which can again help the child to be
included in a regular class. Environmental modifications fare, for example: you give him
good contrast, you make him sit in a place where there is better lighting, with these
modifications a child’s visual functioning can be definitely improved.
Myths and Facts of Visual Impairment:
It is interesting to know that how many myths are associated with visual impairment, for
example: people believe that if a person is low vision s/he should not use his/her vision
at all on the contrary a person who has limited vision what we call the residual vision
should be encouraged to use it as much as possible. Many a times we observe children
bringing their books too close to their eyes and we dissuade them from doing that
thinking that they will lose whatever vision they have again but the fact is that they may
