Visual impairment – Causes and Characteristics

¢Visual impairment is related to visual acuity. The person whose visual acuity is less than 6/60 after glass correction may be termed as visually impaired.

¢This term does not include with normal or near normal vision.

¢It refers to those people whose visual acuity is so defective that they cannot perform their routine life activities independently.

Four Categories of Visual Impairment

¢Profoundly Impaired: Totally blind

¢Severely Impaired: Partially blind whose visual acuity is less than 6/60 after maximum correction.

¢Moderately Impaired: Their impairment is not very serious . They have visual acuity is in between 6/24-6/60. They can do each and everything if proper help is given.

¢Mildly Impaired: Such a visual problem is general in nature. This does not disturb on person in any way in doing any visual task. They generally do not have any restriction in their visual field.

Characteristics of Visual Impairment

General Characteristics

According to research visually impaired people have better capacities for focal and sustained attention in comparison to normal vision people.

Educational Characteristics

As far as absolutely blinds are concerned, touch and audition are the two important sources of information

¢For partially blind vision is limited, they cannot see far away and cannot read a book of less then 12 point in size of letters.

¢They rely more on memory and hearing power.

Physical Characteristics

¢Their motor skills are also found poor due to poor mobility power.

¢In terms of size and appearance, people with impaired vision do not differ from normal people though their health may be somewhat poor due to less mobility.

¢Delayed development of locomotor behaviour is seen.

Cognitive Characteristics:

Cognitive development is the development of concepts.

¢In most of the cases concepts are developed through visual means.

¢Thus visually impaired children may have poor cognitive power.

¢They have to count on auditory or factual abilities in order to get information.

¢Visual impaired child is unable to gather observatory experience.

Behavioural Characteristics:

¢Visually impaired people  are generally very irritative in nature due to hard treatment by others.

¢They possess poor self confidence. Due to this they try to avoid people and situations.

¢Non academic skills affected by visual impairment are social skills, affective understanding and non verbal behaviour.

Communication Abilities

¢They have difficulty in reading.

¢Their communication may be poor in initial periods of their lives but after 18 they are found to be normal.

¢They prefer oral to written communication and do not like to read or write too much.

Social development and Adjustment

¢They are devalued by normal children and thus they begin to develop inferiority complex which leads to maladjustment in the school and neighborhood.

¢Partially blind children do not lag behind the normal children in social development and adjustment

Causes of Impaired Vision

¢Hereditary causes

¢Environmental causes:

Small pox is an important cause of  visual impairment in India.

¢Malnutrition is a major cause of visual impairment in poor/less developed nations.

¢Diseases of the central nervous system

Identification of Visual Impairment

Behavioural Symptoms

¢Inattentive during map work or blackboard work.

¢Complains visual blurring

¢Cannot sit for reading or writing for a longer period of time

¢Complaints dizziness

Physical Symptoms

¢Chronic eye irritation or watery eyes

¢Constant headache ¢Nausea, double vision or blurr vision.

¢Unable to identify small details in picture

¢Regular blinking ¢Constant redness

¢Difficulty in reading small prints

Medical Examination

After examining suspected children they should be brought to eye hospital for eye checkup.

¢If the child is able to read only the letter at the top of the chart, his visual acuity is 6/60.

¢If he is able to read the second row of letter also, his visual acuity will be 6/36.

¢If he is able to read the second last line on the chart , his vision will be considered normal i.e. 6/6.

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