Blindness - full persistent loss of vision in both eyes (no light perception, vision zero). In practical and social relations the concept of blindness is much wider. There are so-called domestic blindness, when lost the ability to navigate in the environment, and professional - losing the chance to do the things even when using any optical devices. To the category of almost blind include people who have light sensation may be preserved, but some residual vision is 0,01-0,02. The decrease of visual acuity without apparent objective changes of organ of vision called amblyopia, vision loss - amaurosis.
According to the census of the late 19th century, in Russia the ratio of blindness (the number of blind per 10 000 population) amounted to 19.7. After the great October socialist revolution in connection with the growth of the cultural and material living standards of workers, improvement and preventive orientation of health services has decreased the number of eye diseases and respectively, the number of blind. On January 1, 1961, the coefficient of blindness around 7.0.
Causes of blindness can be different. Congenital blindness depends on prenatal diseases or malformations of the fetus. The acquisitions include the following forms of blindness: 1) blindness caused by diseases of the eye; 2) blindness caused by diseases of the Central nervous system. (meningitis, encephalitis and other); 3) blindness caused by common diseases (e.g., influenza) or poisoning; 4) traumatic blindness associated with damage to the optic analyzer (eyes, pathways, the visual centers).
On the first place in the statistics of causes of acquired blindness is glaucoma, on the second - trachoma (in those countries where it is still common), on the third - eye injuries. Cases of blindness from the disease of the cornea, the optic nerve and retina are observed less frequently.
Often the loss of vision is marked in the age of 10 and older than 50 years. This is because children diagnosed congenital blindness and there is loss of vision from common childhood eye, and common diseases and eye injuries. In patients older than 50 years cause of blindness are glaucoma and vascular diseases.
In the fight against blindness is essential prevention of eye disease and injury. A positive value is adopted in our country the method of the regular medical service of patients with glaucoma (see).
Prevention of accidents in the workplace should minimise the possibility of eye damage.
The great value has the sanitary-educational work among children and parents, reasonable leisure activities.
The success of eye surgery, in particular the operation of transplantation of the cornea, has allowed some people that are blinded by the dimness of the cornea, restore vision.
The employment of blind people in our country allows them to work in a number of professions. Employment of the blind, cultural and political-educational work carried out by the societies of the blind. The Central Board of the blind be elected and are in Moscow and the capitals of Soviet Union republics. For the blind, there are special libraries with the Fund of books relief in Braille and flat type. Blind study typing, as well as the letter cursive. In enterprises where there are blind, there are special system of protection of labor and safety.
Education of blind and visually impaired children in our country is necessary. In school blind accept children absolutely blind and with residual vision to 0.05. Children with visual acuity from 0.05 to 0.2 enrolled in schools for the visually impaired, which use the font for sighted with increased letters, magnifiers, and other tools that help improve vision. In schools for the blind use a variety of learning methods and teaching AIDS based on the use of hearing and touch. The attention is paid labor and Polytechnic education; students are not only General education but also a specialty.
Blind people have the right to study in higher educational institutions, graduate and get academic degrees and titles.