2. •Sensory impairment is when one of your senses; sight ,hearing , smell, touch , taste
is no longer normal.
Examples-if you wear glasses you have sight impairment ,if it is hard to hear or have
a hearing aid then you have a hearing impairment.
A person does not need to have a full loss of a sense to be sensory impaired.
It is the combination of both hearing and sight impairment .It is not necessarily a
total loss of both the senses-indeed the majority of dual sensory impaired people do
have some degree of sight and/or hearing.
DEAFBLIND
When a person has difficulties in both seeing and hearing then the person can be
termed as deafblind.
Deafblindness is a unique and extremely complex disability that often requires
specialist communication methods and it has adverse effects on all areas of
development , in particular the language adopting process , conceptual
development , motor development , behaviour and personality of a person.

3. THREE COMBINATIONS ARE POSSIBLE:
1) Individuals who are born blind and later develop a hearing impairment.
2) Individuals who are born deaf and later develop vision impairment.
3) Individuals who are born sighted and hearing , but later develop a vision and
hearing impairment
CATEGORIZATION
People who are deafblind can generally be divided into two groups:
Congenital deafblindness
People who were born with a hearing and a vision impairment.
This category may also include individuals who are born hearing- sighted , but who
become deafblind through some accident or illness within the first months of their
lives. The important factor being that they become deafblind before they had the
opportunity to gain formal language skills.
Acquired Deafblindness
People who develop deafblindness later in life.

4. HEARING IMPAIRMENT
CLASSIFICATION OF HEARING IMPAIRMENTS
10-25dB
26-40dB
41-55dB
56-70dB
71-90dB
Above 90dB
NORMAL
MILD
MODERATE
MODERATELY
SEVERE
PROFOUND
TYPES OF HEARING PROBLEM
1) Conductive hearing loss: It is caused by blockage or damage in outer or
middle ear.
2) Senorineural hearing loss: It is caused by damage to , or malfunction of the
cochlea (sensory part) or hearing nerve (neural part).
3) Mixed hearing loss :It results when there is a problem in both the conductive
pathway (in the outer or middle ear) and in the nerve pathway (in the
inner ear)

5. CAUSES OF HEARING LOSS AND DEAFNESS
The causes of hearing loss and deafness can be divided into congenital causes
and acquired causes.
CONGENITAL CAUSES
Congenital causes lead to hearing loss being present at or acquired soon after
birth. Hearing loss can be caused by hereditary and non hereditary genetic
factors or by certain complications during pregnancy and childbirth including ;
1)
2)
3)
4)
5)
Maternal rubella , or other infections during pregnancy.
Low birth weight.
Birth hypoxia
Inappropriate use of toxic drugs during pregnancy.
Severe jaundice in the neonatal period , which can damage the hearing nerve
in a new born baby.

6. ACQUIRED CAUSES
Acquired causes lead to hearing loss at any stage.
1)Infectious diseases such as meningitis , measles can lead to hearing loss , mostly in
childhood but later also in life.
2) Chronic ear infections , which commonly presents as discharging ears , can lead to
hearing loss. In certain cases this condition also leads to serious life threatening
complications .
3) Collection of fluid in ear can also cause hearing loss.
4) Use of toxic drugs at any age , such as some antibiotic and antimalerial medicine
can damage the inner ear.
5) Head injury or injury to ear can also cause hearing loss.
6) Excessive noise , including working with noisy machinery , and exposure to loud
music or other loud noises , such as gunfire or explosions can harm a person hearing.
6) Age related hear loss is done by degeneration of sensory cells.
7) Wax or foreign bodies blocking the ear canal can cause hear loss at any age. Such
hear loss is mild and can be readily corrected.

7. IMPACT OF HEARING LOSS
FUNCTION IMPACT
One of the main impacts on hearing loss is on the individual ability to
communicate with others. Spoken development is also delayed in children with
deafness.
SOCIAL IMPACT
Limited excess to communication can have a significant impact on everyday life ,
causing feeling of loneliness , isolation and frustration.
ECONOMIC EFFECT
In developing countries children with hearing loss rarely receive any schooling .
Adults with hearing loss have a very high unemployment rate .Among those who
are employed , a higher percentage of people with hearing loss are in the lower
grades of employment compared with general people.

8. TYPES OF BLINDNESS
1) MYOPIA OR NEAR SIGHTEDNESS
In this defect we see the nearly objects clearly but after a certain distance either
we see blurd or unable to see the object.
RECTIFICATION OF MYOPIA
Generally convex lens is used by which light rays are focussed on yellow point of
the retina and create a clear image.
2) HYPER MYOPIA OR FARSIGHTEDNESS
In this defect the long distance object can be seen clearly at closer distance -25
cm , approximately focus is not possible.
RECTIFICATION OF HYPER MYOPIA
A concave lens of suitable focal length is used for rectification of hyper myopia.

9. PRESBYOPIA
This is the defect in both short and long distances . For such cases bifocal lens are
being used . The upper lens is convex lens and is used for long distance and the
lower lens is concave and is used for short distances.
ASTIGMATISM
In this defect objects are seen blurred either in horizontal or in vertical direction .
In such cases cylindrical lenses are being used to rectify the defect.
COLOUR BLINDNESS
There are two types of nerves sensory nerves found at retina . The rod types
nerves which are concerned with the density of light and the cone type nerves
which are sensitive to colours . If the number of the conical shape nerves
decreases at the retina , the person become unable to identify colour
properly.The defect is permanent in such cases.

10. CAUSES OF BLINDNESS
1) CONGENITAL :Some children are blind by birth .
2) POST- BIRTH :Some children become blind as a result of sickness or
some injury to the eye or some disability to the brain or due to
malnutrition or infection .Some post birth causes are below:
a)NUTRITIVE BLINDNESS .
b)Some infectious diseases also lead to blindness , such as conjunctivitis .
c)GLAUCOMA: This develops due to excessive pressure within the eyeball .
c)RETINITIS PIGMENTOSA : It makes the retina slowly grow thinner , the
area of vision continually decreases , leading to blindness .

11. RETROLENTAL FIBROPLASIA :
In this disease , due to the presence of excessive oxygen in the eye , the retina gets
detached from the eye and the person becomes blind.
MEASLES :
It affects the pupil and the eye sight gets affected . The person may also become
blind .
BRAIN INJURIES :
Due to cerebral palsy , brain infection , or oxygen shortage at the time of birth ,the
brain gets injured . This can lead to blindness .
EYE INJURIES :
An individual becomes blind due to some injury to the eye from a pointed object or
from fire .
DIABETES:
Increase in percentage of sugar in the blood lead to blindness .
HIGH BLOOD PRESSURE:
Due to excessively high blood pressure , the blood gets clotted in the veins of eyes
which leads to blindneess .

12. PREVENTIONS OF HEARING LOSS AND BLINDNESS
It is generally said that little precaution has more significance than a cure .
1) Avoid marriages amongst close relatives .
2) Immunize adolescent girls and women in child bearing age against rubella
3) Expectant mother should avoid contact with person suffering from
infectious diseases .
4) Ensure good health of expectant mother – seek health check ups at
regular interval .
5) Make sure that the delivery is performed under the supervision of a
trained person .
6) Follow the child immunization schedule properly .
7) Maintain good ear and eye hygiene of the children .
8) Do not swim in dirty or highly chlorinated water ,as they affect ear and
eyes .
9) Do not apply homely products in ear or eye without any consultant.