Information Sensory Impaired
Sensory disability includes:
1 - Deaf, deafened and hearing impaired people
2 - Blind and visually impaired people
3 - Deafblind individuals
Sensory impairment can result from trauma and from conditions/diseases affecting:
o Hearing (e.g. age-related hearing loss, tinnitus, Méunière´s Disease)
o Seeing (e.g. glaucoma, macular degeneration, diabetes)
o Speaking (e.g. muteness)
o Multiple senses (e.g. autism, epilepsy)
Hearing Difinition:
Hearing (or audition) is one of the traditional five senses. It is the ability to perceive sound by detecting vibrations via an organ such as the ear.
The inability to hear is called deafness.
In humans and other vertebrates, hearing is performed primarily by the auditory system: vibrations are detected by the ear and transduced into nerve impulses that are perceived by the brain (primarily in the temporal lobe). Like touch, audition requires sensitivity to the movement of molecules in the world outside the organism. Both hearing and touch are types of mechanosensation.[source Wikipedia]
Deaf, deafened and hearing impaired people
An athlete is categorized to have an auditive limitation when he/she, without the aid of a hearing aid, doesn’t hear more than 55 decibel on the ear with the best hearing level.
Sign language
Somebody who was never able to hear doesn’t even know what sound is. In this case it is not logical to learn a “native” language based on sound. For the deaf a visual “first” lan-guage goes without saying a sign language therefore.
That is the reason behind the statement 'sign language is the natural language for people born deaf'.
Full fledged language
Sign language has an own vocabulary, own grammatical and own expressions. It is a full-fledged language where a skilled “signer” can say everything he or she wants to say.
Sign language can be used from a light conversation up and until a heated meeting, from emotional debate towards sensitive poetry. The opinion that sign language is a kind of pantomime is therefore absolutely wrong. Just like the auditive oriented languages the sign language is came into being in a natural way. Sign language is not “invented” and for sure not derived from auditive languages
One Dutch sign language
In the Netherlands the Dutch sign language (NGT) is used. People often think that in the Netherlands different sign languages exist this is not the case. The grammaticism of the NGT and many expressions are the same al over the Netherlands and is an official lan-guage. However there are 5 existing variants (like dialects), which originated based on the 5 major education centres for the deaf in the Netherlands. For the “starter” in sign lan-guage these dialects are some times confusing. An experienced “signer” however can “read” the dialect without any problem
World Games for the Deaf (as of 2001 Deaflympics)
The World Games for the Deaf, sometimes called the "Silent Games" are the oldest con-tinuing games outside of the Olympics. In 1924 133 athletes from nine nations gathered to participate in Athletics, Cycling, Football, Shooting and Swimming. 2700 athletes from 63 nations participated in 1996 held in Denmark.
Blind and visually impaired people
Sight Definition
The visual system is the part of the nervous system which allows organisms to see. It interprets the information from visible light to build a representation of the world surrounding the body. The visual system has the complex task of (re)constructing a three dimensional world from a two dimensional projection of that world. The psychological manifestation of visual information is known as visual perception.[source Wikipedia]
SHARPNESS OF SIGHT or VISION
Sharpness of sight is the degree in which we can see details; the capability to dis-tinguish two points that are near to each other.
Sharpness of sight is expressed in the formula V = d/D.
V = vision or sharpness of sight
d = distance of a person to a letter chart
D = the distance from which a ‘good’ (emmetropic) eye can
recognize a letter.
(In other words: the test-distance divided by the normal distance.)
Sharpness of vision is measured by an oculist or optician. To do so he uses a letter chart. Every chart is standardized for a certain distance: 3, 5 or 6 metres. A person is asked to read the letters, from top to bottom. When he reaches the bottom, he has a vision of 1 or:100%.
When someone only gets halfway down this corresponds with a certain vision value. This value is expressed in a percentage or fraction. For example 20% or 2/10.
These percentages are fractions or ordinary fractions
This means that the person in question finds it difficult to see details. When some-one has a vision of 2/10 it means the he, from a distance of 2 metres, can see the same details as someone with ‘good’ vision can see from 10 metres. A person with good vision will be able to see which shape of leaves a tree has from 10 metres. A visually impaired person will have to walk up to the tree in order to see whether he is looking at a beech or an oak tree.
In case of severe visual impairment the following methods are used:
• counting fingers at 1 metre = 1/60
• observe hand movement at 1 metre = 1/300
• light/darkness perception = only light or dark is observed.
At a vision of 0,3 there will probably be difficulties with reading.
The development of vision only ends at the age of four.
The sharpness of sight we reckon with is the value one achieves after op-timum correction.
FIELD OF VISION
Definition:
The field of vision is that part of a space which is perceived when the eye is fixed on a certain point.
The field of vision that is seen with two eyes at the same time is called the binocu-lar field of vision. Usually the limit of the field of vision to the temple side is about 90-100 degrees, to the side of the nose 50 degrees, up and down 50-60 degrees.
The sensitivity of the retina depends on the place of the retina:
In the centre, near the macula, sensitivity the high. Here one can see details and colours well because here are only cones the nerve cells that are responsible for registering colour and detail.
In the periphery sensibility is low. There one cannot see details, only that there is something. As far as seeing colour is concerned: in the periphery only large, brightly coloured surfaces are perceived, not small, softer coloured ones. This is because here are more staves??? and far less cones.
Characteristic of the periphery is that moving objects are better observed than im-mobile ones. This is what we make use of in traffic and other mobile situations.
The field of vision is measured in a field of vision test or perimetry. The central field of vision can be measured more closely with the Amsler test. Field of vision is expressed in degrees.
Field of vision describes the function of the whole retina; sharpness of vision de-scribes the function of the ‘fovea’(the central part of the macula) when the eye is fixed on a certain point.
Only the point the eye is fixed on can be seen with clarity. Objects are seen less clear as the angle between these objects and the point of fixation increases.
Various eye diseases can cause loss of field of vision.
Conclusion:
The World Health Organization Visual impairment is defined by a visual acuteness equal to or less than 3/10 or a range of vision less than 30 degrees. People with a visual acuteness of more than 3/1 or a range of vision of more than 30 degrees are not visually impaired according to this definition.
This classification is a formal one. In reality it is difficult to distinguish between good sight, visual impairment and blindness. Most people are able to see smaller objects when they reduce the sight distance. For example, there are people with a visual acuteness of less than 1/20 who are still able to read a paper with help from a magnifying glass. Most of the above mentioned blind people are able to see just a little. Important for our observation is the so called ‘visual efficiency’.
This is a combination of:
• Visual memory
• Perception
• Cognitive skills
• Capacities (learning possibilities)
• Factors that influence motivation.
Someone who becomes visually impaired later in life has already created a visual memory, therefore these judokas will behave and move differently from judokas who have had a visual impairment from birth.
Visually restricted judokas have an Olympic status: male judokas since 1980, fe-male judokas since 2004. The only difference between judo matches at the Para-lympics and other judo events are the measures taken to mark the safety zones. The level of competition of a blind or visually impaired person seems not to differ from that of a sighted judoka. The VI judoka mainly has different strategies from a sighted judoka.
Deafblind individuals
Deafblindness
is the condition of little or no useful sight and little or no useful hearing. As with the word "Deaf," it can be capitalized to indicate that it is a culture; some prefer the spelling "DeafBlind". Deafblind people have an experience quite distinct from people who are only deaf or only blind
Acquired
The majority of people with sight and hearing impairments have had both sight and hearing throughout most of their lives, and experienced a loss of those senses through illness, injury or age. According to sense.org.uk, about 4% of people over 60 in the UK have both hearing and vision impairments. Most people with acquired sight and hearing loss retain some useful sight and/or hearing. Some people have congenital deafness and acquired blindness (such as glaucoma or cataracts) or vice-versa.
Congenital
Children born deaf and blind are described as having congenital deafblindness. This condition may be due to prenatal infection (such as rubella), genetic/chromosomal syndromes (such as Down syndrome), birth trauma or maternal heavy alcohol and drug use. Some congenital conditions will not cause deafblindness until later in life. Sense.org.uk reports that the biggest cause of deafblindness in children in the western world today is 'unknown.' Maternal rubella was once the major cause of deafness and deafblindness in the west, but is now rare due to widespread vaccination programs. [source Wikipedia]
