In Germany, a person is blind in the sense of the law if, even with glasses or contact lenses, he or she can see less than 2% of what a person with normal vision can see. A person is classified as “visually impaired” if, with glasses or contact lenses, he or she has less than 1/3 of the vision of people with normal vision.
Blindness and gender
Blindness and visual impairment affect men and women equally. For all age groups up to about 60 years, the distribution of blindness cases is the same. However, because the ratio of the sexes shifts in favor of women with increasing age, more than 2/3 of those affected by blindness and visual impairment in the 60+ age group are female!
Blindness in Germany
There are about 145,000 blind and over 500,000 visually impaired people living in Germany. Here is a table of the age distribution in different age groups.
| Age group | Age distribution in percent | Age distribution absolute |
|---|---|---|
| <18 | 6% | 8.700 |
| 18-30 | 7% | 10.150 |
| 30-60 | 17% | 24.650 |
| 60-80 | 32% | 46.400 |
| >81 | 38% | 55.100 |
Blindness worldwide
There are approximately 37 million blind and 124 million visually impaired people worldwide. Every 5 seconds, one person on earth goes blind, and 90% of blind people live in developing countries. There, people have a 10 times higher risk of going blind than in industrialized countries. The main reason for this is poverty and the resulting lack of medical care, including in the field of ophthalmology. For example, one ophthalmologist in Africa is statistically responsible for one million people, compared with around 13,000 in Germany.
Blindness in developing countries
Blindness in developing countries forms the beginning of a vicious circle. This is because 90% of blind children are denied schooling and 80% of blind adults are without work due to a lack of educational opportunities. They and their families therefore have little chance of escaping poverty. Yet 75% of blindness worldwide could be prevented. This is because these are eye diseases that can be prevented or cured by simple means and therefore remain without serious consequences in our western industrialized nations, but are the most common causes of blindness in poverty-stricken developing countries.
Causes of blindness in central Europe
According to WHO data, blindness in Central Europe is caused by the following diseases:
- Age-related macular degeneration 50%
- Glaucoma 18%
- Diabetic retinopathy 17%
- Cataract 5%
- Corneal opacities 3%
- Blindness in childhood 2.4%
- Other causes 4.6%.
Cataract
Occurrence: About 17 million people – mainly in Asia and Africa – are blind from it. This makes cataracts the most common cause of blindness worldwide. Causes: On the one hand, senile cataract, usually caused by metabolic diseases and aging of the tissue, but on the other hand, it can also be congenital or inherited (including rubella of the mother during pregnancy) or caused by injuries. Treatment: Star-blind people – after all, half of all blind people – can have their eyesight restored by surgery. This involves removing the lens that lies behind the pupil and has become opaque. With cataract glasses or the implantation of an artificial lens, the operated patients can see again. Average cost: 30 euros, for children about 125 euros. More than 600,000 cataract operations were performed last year in CBM-supported hospitals (CBM = Christoffel-Blindenmission).
Trachoma
Occurrence: 84 million children, women, and men in Africa, Southeast Asia, Central and South America, and the Middle East suffer from trachoma infection. 1.3 million people have already suffered incurable blindness from it. Cause: An infection, favored by water shortage, hygiene problems, insufficient health care, poverty as well as massive occurrence of flies, which transmit this disease. Ten to 20 years after the onset of the disease, scars form on the eyelid through which the eyelashes grow inward and rub against the cornea. This leads to scarring and clouding of the cornea and eventually to blindness.Treatment: Preventive treatment of the infection in the early stages by regular face washing and tetracycline eye ointment. If the disease is more advanced, minor eyelid surgery helps. Cost: about 15 euros. If trachoma remains untreated, the patient will go blind. With the help of CBM, around 800,000 people were screened and treated for trachoma last year.
Glaucoma.
Incidence: Approximately 4.5 million people worldwide are blind. Cause: Predominantly too high intraocular pressure, which damages the optic nerve. The affected person does not feel any pain at first, so glaucoma is often not noticed until the destruction of the optic nerve is already advanced. Treatment: preventive examinations (measurement of intraocular pressure with tonometer) eye drops, surgery. Vision loss that has already occurred cannot be reversed.
River blindness (onchocerciasis).
Occurrence: In West and Central Africa, South America, parts of the Arabian Peninsula. 290,000 people are incurably blind. Cause: When bitten by the blood-sucking Simulium fly (called black fly), larvae are transmitted to humans and live up to twelve years, releasing millions of microscopic worms (microfilariae). These migrate around the body until they reach the eye and destroy the optic nerve. Treatment: Preventive with the drug Mectizan. It must be taken regularly once or twice a year for ten years. CBM distributes Mectizan in close coordination with the World Health Organization (WHO). Cost: about one euro per tablet distributed. As part of the blanket treatment of onchocerciasis, staff from partner projects have already reached around 3.3 million people. If left untreated, onchocerciasis can lead to blindness.
Vitamin A deficiency (childhood blindness).
Incidence: Between 350,000 and 500,000 young children go blind each year in developing countries. Many of them die within a few years of becoming blind. A total of 1.4 million children are blind. Causes: One of the causes is nutritional vitamin A deficiency (xerophthalmia). It leads to softening and clouding of the cornea with blindness as a consequence. The process is accelerated by measles, for example, because this infectious disease consumes a lot of vitamin A. Treatment: Vitamin-rich diet and preventive use of vitamin A capsules. The distribution of one capsule costs 1 Euro. If a child goes blind as a result of xerophthalmia, his or her eyesight is irretrievably lost. In total, around 830,000 vitamin A capsules have been distributed by CBM.
