However important would be four of our senses , hearing, sense of smell, taste, sense of touch, for all people, there is no doubt that the most important sense is sight. By sight we perceive 80% of all input from our environment and damage or loss of sight would be the worst sense handicap for the most of people. Using quotation of Jára Cimrman:
You don´t have to like it, you don’t have to agree with it…but that’s all you can do about it. “
There exists a range of visual impairments. Short-sightedness, long-sightedness, old age long-sightedness and stigmatism count among the most common disorders. Also disorders of eye movement muscles, night blindness, defects of colour perception, glaucoma and cataract cause severe problems. Among the most severe eye disorders count pathological changes of retina and its vessels: degenerative illness of retina of inflammatory type, inflammation of retina, detached retina, changes of target of an optic nerve, anomaly of iris, absence of lens, congenital defect of vessel layers – curving, tapering, thinning of cornea or some tumour condition.
Visual impairment or vision loss can be also caused by an accident. Besides mechanical sight damage, which is the most common type of an eye injury, there are other possibilities that may cause visual impairment such as radiation, warmth, electricity, direct contact with acid or lye or damage by lacrimators.
Unless it is possible to heal a particular eye defect with medicines or correct it by using common optical tools such as glasses and contact lenses or when even a nowadays common laser correction of sight won’t help, the only option left is surgery. E.g. For patients with cornea defect, such as deformation, thinning or after an injury, who cannot use any helpful treatment, the only remaining possibility is transplantation.
Apart from injuries we can also talk about inherited illnesses, cornea defects caused by various inflammations, or possible gradual degeneration of this original clear tissue, which lead to its complete blurring. Considering the low number of donors, waiting time is about 3-4 months. However, healing itself takes much longer time; therefore, the final evaluation of surgery can be done after a lapse of one year. Common intraocular surgeries are, removing of patient’s blurred lens and implantation of artificial intraocular lens.
Is it possible that blind people would see again?
Regarding the above, there are two major independent research studies undertaken in the world today, the results of which should be a microchip that enables blind people to see again. We can assume according to existing results that substitute of sight by this implant should be possible in future. However, meanwhile none of these projects have reached the stage of clinical testing on people. It is not possible to give sight to people, who were born as blind. Their optical system hasn’t evolved normally within their embryonic ontogenesis and consequently the cells transmitting the electric signals to the brain are not functional. In this case an electric signal of an artificial retina would have to be transmitted through electrodes directly to brain.
Life with visual impairment
Visual impairment brings severe complications to life. It is recommended to use the help of an ophthalmologist as much as possible. If they cannot help, there are organizations helping such handicapped people as well as their environment. It is better to learn how to live with this handicap rather than wait for a cure. Life is beautiful even though one cannot look at many things. It is necessary to live life not only to exist.
Visually handicapped people are people with various types and levels of visual impairments. We use this term to determine people whose damage of sight affects activities of their daily life and where regular optical correction is not sufficient. People wearing dioptric glasses, who can normally see do not count among this group. These people have a light sight defect and are able to do everyday activities without any serious complications. They are not limited in getting information, orientation, self-reliant movement, work, social environment etc.
The group of severely visually handicapped people can be further divided in the purblind and the blind. During the eye examination it the visual sharpness is checked, which is expressed in fractions, where the first number states distance in meters which the person reads from, and the second number states the same distance, which the person with the sight defect reads from. (E.g. a healthy eye=6/6). Examination of visual sharpness for a long distance is most often made on so called “Snellen ophtotype, which is actually a table with gradually smaller signs. Among another examined parameter counts extent of visual field. This field may be tapered in consequence of a sight defects. It may come up sometimes to be a so called scotoma (a loss of a visual field).
Statistics about the blind and low vision
According to the statistics of WHO there are 45 million blind people in the world and this number could double in the next 20 years. There are 11 million of people with low vision and about 1 million blind people according to the British sources in Europe. One in every 60 people in Great Britain is severely visually handicapped. Other sources state that there are about 1-1.5% of population with visual handicap. Precise statistics do not exist even within individual countries.
It is interesting that 9 out of 10 blind people live in developing countries and professionals estimate that 80% of all cases might be healed or prevented.
Also worth mentioning that the percentage of the low-visioned in the population is gradually growing and one of the decisive factors affecting this trend is certainly beyond any doubt, prolonging length of life. (This is valid mainly for our Euroamerican civilization) Direct proportion of sight defects origin and growing age is unambiguously proved: 80% of people older than 75 years have severe problems with their sight and 70-75% of sight defects appear in people older than 65 years. Thus we can draw a conclusion that aging is an important factor conducive to the appearance of sight defects. Prognoses state that in the next 20 years the number of people older than 85 years will double. Consequently, we can deduce an increase of visually handicapped people.(Source: web sites of Union of the blind and the purblind in the Czech Republic and magazine Revue of discovers, science, technique and people of 21 st century)