Blindness

Synonyms

Medical: Amaurosis

English: blindness

definition

Blindness is a profound loss of vision caused by illness, injury or birth, and which leads to a serious break in normal life.

causes

Blindness can be a slow process in which eyesight progressively deteriorates, or blindness can be sudden. There are different causes for these two cases. Sudden blindness occurs as a result of massive trauma that can result from accidents. In addition, the artery, which is largely responsible for the blood supply to the eye, can become blocked. Deposits in the artery or a thrombus can block the artery so that the retina is no longer adequately supplied with oxygen.

An acute increase in intraocular pressure, inflammation of the eye skin, which is also called uvea, vitreous hemorrhage and retinal detachment are other causes of sudden blindness.

In contrast to this, slowly progressive blindness is caused by age-related changes in the macula (macular degeneration), the point of sharpest vision on the retina. Consequential diseases of diabetes, infections or cataracts are other possible diseases that can cause blindness. Depending on the cause, both medicinal and surgical therapy can be used.

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Social aspects of blindness

With the loss of eyesight, there is also a massive cut in the life of the person concerned. The loss of eyesight must be compensated as well as possible by other sense organs.
Everyday routine tasks (e.g. walking on public roads and in unfamiliar surroundings) become a challenge in the case of blindness. Those affected by blindness are also dependent on help from others in an unusual way.

Above all, it is important that patients with blindness find their way back to life as well as possible. In the meantime, it has become possible for the blind to earn a living again in special professional institutions if the originally exercised profession no longer offers an opportunity due to the illness.

There are numerous aids that blind patients can use to find their way back to normal and everyday life. This includes prescribing and training with a long stick for the blind. This is a mostly white stick with a corresponding extension at the end of which a ball or roller is attached. With the help of this stick, the patient can feel the ground in front of him, detect and avoid bumps and obstacles.

Blind patients often pull the stick along edges (e.g. curbs or platform edges) in order to be able to estimate the exact limit. Training with a long cane for the blind should last 80 hours and be prescribed by the doctor.

Some people affected by blindness also opt for a specially trained dog, which they lead in a special harness and which also warns of obstacles and the patient e.g. leads across streets.
Today it has become less common to mark blind people in relation to their surroundings. The internationally recognized sign of blindness is three black dots on a yellow background that are in the form of a triangle.

These symbols are still worn today in the form of buttons, the armbands that were mostly used in the past are rarely seen today. The way sighted people deal with those who are blind, as many cannot deal with the situation, causes many problems. Sighted people often want to rush to the help of the blind and give them e.g. Help across the street, but this is usually not in the interests of the blind who have already adapted to their new life.

Associations of the blind give the tip that one should help calmly, but should first wait for the request of the blind person.
In the vocational training of blind people, a distinction must be made between whether blindness has been present since childhood or whether it occurred later.

Vocational training organizations or professional development organizations take on the training of disabled people and develop special programs. In addition to vocational training, there are now a large number of schools for people with blindness, which are supposed to bring the learning content closer to the pupils using special scripts and books.

Braille refers to characters that are embossed from the flat paper surface of e.g. Books are sublime and can be felt by the reader.

There are now numerous guidelines on how to prevent blindness. Numerous occupational health and safety regulations have been issued to prevent damage to the eye. In addition to regular preventive examinations at the ophthalmologist, a full correction of ametropia eyes is recommended, if necessary with glasses.
In addition, particular importance is attached to adequate lighting in the workplace and in the living rooms. For example, TV should not be viewed in completely darkened rooms and a source of lighting should be placed behind the TV set.

Concomitant symptoms

In the case of blindness, two different causes have to be distinguished in order to describe the different symptoms. On the one hand, blindness can be congenital. These patients are born with it, grow up with blindness, and learn to cope with it. They also don't know what it's like not to be blind. This is not the case with acquired blindness through diseases such as glaucoma (glaucoma) or age-related macular degeneration, which leads to creeping blindness and patients often have little time to adjust to it.

Newborn babies cannot always be seen directly whether they are blind. They often show other symptoms. They tend to be less aware of the environment and recognize bad faces. In addition, they often find it difficult to fixate on objects, etc. In addition, the lenses or strabismus can become cloudy. Frequent rubbing of the eyes can also be a first sign. When completely blind, it is impossible for the eye to perceive light.

With acquired blindness, the symptoms usually come insidious or direct blindness occurs as a result of an accident. A vascular occlusion can also lead to acute blindness. With the insidious visual impairment, the patients can no longer perceive the environment clearly. Frequent pushing or falling is typical for the patient.

The social aspect is also important. Increasing blindness could make it more difficult for patients to go outside. Social withdrawal is the result. Depression is also a common consequence of sudden blindness.

Blindness from methanol

Methanol is an alcohol, the consumption of which is toxic to the body as it is converted into two harmful products in the liver. These are formaldehyde and formic acid. Both substances can only be broken down very slowly and accumulate in the body. Formic acid leads to life-threatening acidification of the body, which makes it difficult to transport oxygen, and formaldehyde is poisonous for some organs, especially the liver, kidneys and heart. The unwanted absorption of methanol usually occurs when the alcohol used in high-quality alcoholic beverages is diluted with methanol, or when a schnapps is brewed incorrectly by a private person.

Depending on the dose, methanol poisoning has different harmful effects. In the eye, methanol poisoning initially causes a deterioration in visual acuity a few days later. This leads to massive damage to the central nervous system and especially the optic nerve, which can lead to blindness. This can only be prevented by early therapy. Therapy is usually carried out by administering ethanol or fomepizole. These two substances bind to the enzyme that normally converts methanol into its toxic products in the liver, thereby preventing the processing of methanol.The supply of ethanol must be maintained until the entire amount of methanol absorbed has been excreted via the kidneys. In addition, a drug with a basic effect is given, which is supposed to compensate for the acidification caused by the formic acid.

Blindness from alcohol

When it comes to the production of alcohol, we first talk about ethanol, the breakdown product of sugar. Yeast utilizes sugar, but also other substances such as carbohydrates that the human body cannot break down on its own. This creates numerous by-products of ethanol, which in various quantities can be very toxic to the body.

Alcohol is generally harmful to the human body and various types of alcohol, such as methanol or isopropanol, can lead to blindness. Both are used as ethanol substitutes, which should actually be used in high quality spirits, or they are produced as a by-product of fermentation.

Isopropanol leads to inflammation of the conjunctiva and irritation of the mucous membranes, whereas even small amounts of 5-10ml of methanol can lead to severe damage to the optic nerve with blindness. In addition, there may be visual disturbances and temporary disturbances in sensory perception due to the interaction of alcohol and some medications.

In addition to blindness, frequent symptoms of regular alcohol consumption are nausea, headaches, neurological disorders such as memory lapses, impaired consciousness and behavior, massive liver damage, respiratory depression, wetting and hypothermia.

Blindness from glaucoma

Glaucoma is also known as glaucoma and describes all diseases that lead to pressure in the eye and thus to a pinching or compression of the optic nerve and, as a result, visual loss up to changes in the optic nerve papilla, i.e. the point where the optic nerve meets the eye leaves, as well as total blindness. Glaucoma is caused by a disruption of the balance between the formation and drainage of water in the eye chambers.

There is either an overproduction or an obstruction to drainage, which can lead to an increase in intraocular pressure. Triggers can be drugs, interventions or trauma. Early detection of glaucoma is important to prevent blindness. Signs of glaucoma can include clouding of the cornea or enlargement of the eyes.

Preventive measures, including measuring intraocular pressure, are also very important, because glaucoma is the second most common cause of blindness in industrialized countries. As a therapeutic measure, drugs can be given to constrict the pupils, which facilitate drainage of the aqueous humor. There are also drugs that inhibit aqueous humor production and improve drainage and blood flow in the chamber. The drainage can also be improved operationally by opening the designated channel.

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Blindness from smoking

The toxins inhaled through smoking cigarettes can lead to thickening of the vessel walls over a long period of time and thus also to a reduction in blood flow to the eye. As a result, this can trigger cataracts or premature macular degeneration, which can continue to lead to blindness. In macular degeneration, the sensory cells that are responsible for the visual process and are located on the retina, in an area called the macula, perish.

Normally, macular degeneration is an age-related disease from the age of 50, which can start much earlier due to smoking. In addition, the inhalation of cigarette smoke increases the release of oxygen radicals that can damage tissue. Degradation products of the metabolism can no longer be adequately disposed of and are also deposited in the tissue. In addition to this burden, the smoker usually has a reduced intake of vitamins and trace elements. However, these are essential for the supply of body cells. If there is any suspicion of the onset of macular degeneration through smoking, consumption should be stopped immediately and vitamin deficits should be compensated for.

Stroke blindness

A stroke is a sudden disruption of the blood supply to the brain in which brain tissue dies due to a lack of oxygen and nutrients. The blood supply can be blocked by a vascular occlusion or cerebral hemorrhage can occur, the risk of which is increased due to arteriosclerosis and high blood pressure. Depending on the affected brain region, visual disturbances can also occur as a result. This includes the half-sided loss of the field of vision, which means that the patient lacks either the right or the left side of his field of vision in both eyes. This is due to a direct lesion of the optic nerve. These cannot be remedied, instead the patients receive therapeutic compensation training in order to compensate for the missing area of ​​the visual field as well as possible.

Another consequence of a stroke can be the temporary loss of visual acuity, also known as visual acuity, as well as the perception of double images and generally indistinct and blurred vision. The creation of double images is damage to the parts of the brain that are responsible for the movement of the eye muscles. Flickering and short-term blindness can also occur as symptoms. This mainly affects the secondary visual center, which is also responsible for linking what is seen with an association and learned terms.

Read more on the subject at: Consequences of a stroke

Blindness from a solar eclipse

During a solar eclipse, special glasses are increasingly being sold everywhere, with which it is possible to observe the solar eclipse undamaged. Because seeing the solar eclipse with the naked eye can be dangerous.

As the moon moves forward, the sun's rays are bundled and appear particularly bright. In a solar eclipse, unlike in everyday life, we focus directly on the sun. This burns and damages the retina. This phenomenon is easier to visualize with a magnifying glass. If you bundle the light rays with the help of a magnifying glass, holes can be burned through a paper. It's the same with the retina. Since this has no pain sensors, you won't feel the burns at first. Only later do you notice the impaired vision. Some damages are reversible, but others can be permanent. Should a case arise, a doctor should be consulted immediately.

Summary

Blindness is the complete loss of vision due to various inherited or acquired diseases or injuries. A distinction is made between causes that occur mainly in western industrialized countries and causes that occur in developing countries. In western countries, the most common causes of blindness are glaucoma (glaucoma), retinal detachment, diabetic retinopathy, injuries to the eye, inflammation of the uvea (Uveitis) and age-related macular degeneration. In developing countries, cataracts (cataract), trachoma, onchocerciasis and keratomalacia as causative agents. Blindness is a serious intervention in a life that was mostly uncomplicated until then. Blind people have to find their way around their surroundings, sometimes with a guide cane or guide dog, and have to go through retraining programs in a professional sense in order to be able to make a living. Around 160,000 blind people and over one million visually impaired patients live in Germany with considerable restrictions in their daily lives.