In the Night blindness, medical Hemeralopia called, vision is impaired at twilight. This is due to a functional weakness in the rods. These are the sensory cells of the retina that enable vision in poor lighting conditions.
What is night blindness?
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The Night blindness can be congenital, but can also be caused by a disease such as diabetes or a vitamin A deficiency. It depends on how night blindness works. In almost all cases there is no cure for night blindness.
Night blindness in the narrower sense means that you can no longer see anything at night or in the twilight. This is very rare, most patients who are affected by night blindness just see worse at night. In both cases one speaks of night blindness.
causes
The cause of Night blindness is in any case a disorder of the rods. These sensory cells in the retina make it possible to see at dusk. Such dysfunction of the chopsticks can be triggered by many different causes.
Therefore, in the case of night blindness, it is always advisable to be examined by an ophthalmologist. Vitamin A deficiency is very rare in industrialized countries. Vitamin A is necessary for light and dark vision and leads to visual disturbances in the dark if it is not available in sufficient quantities.
A vitamin A deficiency can occur, among other things, if not enough foods are eaten that contain the vitamin or if sufficient intake is not possible due to a stomach or intestinal disease.
Congenital diseases are far more often responsible for night blindness. For some people, the chopsticks just work worse. This form of night blindness is often associated with nearsightedness and eye tremors (nystagmus). However, the rather rare retinopathia pigmentosa can also lead to night blindness.
In this disease, the sensory cells of the retina are attacked by the body's own processes and gradually lose their function. Other physical illnesses such as diabetes can also cause night blindness if the fine vessels in the eye are damaged by the diabetes.
The visual problems that a cataract (clouding of the lens) brings with it are not night blindness in the strict sense of the word. At dusk, patients with cataracts are more likely to notice that their vision is more blurred and that they are blinded by incident light.
By the way, it is normal if you do not see anything for the first few minutes after moving from the light to a dark room. The eye needs a few minutes until it has adapted to changing light conditions.
Symptoms, ailments & signs
With night blindness, vision problems occur in poor lighting conditions. The eye is no longer able to adapt to twilight or darkness and reacts to rapid changes in brightness with vision problems and blindness. Patients often notice a gradual deterioration in their vision at night, often with symptoms such as eye tremors or myopia.
If night blindness is caused by a disease of the retina (such as retinopathia pigmentosa), visual field losses also occur. As the disease progresses, complete blindness can occur in one or both eyes. If a vitamin A deficiency is the cause, hemeralopia is often accompanied by very dry eyes and itching or pain.
In addition, there are other visual disturbances such as color vision disorders and double vision. The symptoms of night blindness can be congenital or as a result of illness or an accident. Mostly people between the ages of 30 and 50 are affected. The hereditary form develops shortly after birth.
The affected children suffer from nearsightedness, visual field deficits and visual problems in restricted lighting conditions already in the first two years of life. A progressive course leads to the fact that the sick in individual cases become partially or completely blind before adulthood.
Diagnosis & course
The ophthalmologist examines to diagnose the Night blindness only the dark adaptation of the eyes, i.e. how well and quickly your eyes can adapt to changing light conditions. An adaptometer is used for this. In addition to dark adaptation, this device can also measure how sensitive you are to glare and how nearsighted you are in twilight.
The causes of night blindness are then searched for. An electroretinogram is also used for this purpose. This device can be used to check the functionality of the sensory cells in the eye: the rods, which are responsible for seeing in twilight, and the cones, the sensory cells, for seeing in color.
The course of night blindness depends on its cause. If night blindness was inherited from parents, night blindness usually does not get worse over time. Retinopathia pigmentosa, on the other hand, gradually leads to greater visual impairment, which also affects night blindness.
Complications
Night blindness in the narrower sense is the complete failure of the rod-shaped photoreceptors, the greatest density of which is on the retina outside the macula, the place of sharp color vision. The rods are characterized by their strong light sensitivity and high sensitivity to moving objects, but they do not convey any color vision. Most of the time, night blindness hides only limited night vision, which is particularly noticeable through an uncomfortably increased sensitivity to glare when driving at night.
If the night blindness is based on a genetically determined malposition of the rods, the restricted vision does not change further at dusk and at night. If night blindness is acquired, the further course depends on the cause. If it is only a matter of a vitamin A deficiency due to a one-sided diet or because the absorption capacity of the intestinal tract is restricted due to an intestinal disease, the symptoms improve when the metabolism can again have a sufficient amount of vitamin A.
If the problems are based on damage to the vascular system in the retina, which can be caused, for example, by an excessively high sugar concentration in the blood due to undetected type 2 diabetes, the prognosis is unfavorable if the disease continues to be ignored and not treated. Another factor that causes night blindness is a genetic retinopathia pigmentosa, which is usually associated with very slow disease progression.
When should you go to the doctor?
Decreased eyesight in the dark is a natural process that does not require investigation or treatment. However, if there are further complaints or if the inability to see begins at dusk, a check-up visit to a doctor should take place. If your own vision differs in direct comparison to that of other people, you should see a doctor.
If the surrounding objects or other people can only be seen vaguely or blurred, a check-up visit with a doctor is necessary. Trembling of the eyes, pain around the eyes, or a headache are signs that the irregularity is present. If there are more accidents or falls due to impaired vision, a visit to a doctor is recommended. Severe myopia or the feeling of blindness with decreasing exposure to light should be examined and clarified. Failures on the face are particularly worrying as they are a clear indicator of an existing medical condition.
If, in addition to the physical impairments, there are also emotional or mental irregularities, a doctor should also be consulted. Behavioral problems, aggressive tendencies, anger and withdrawal from participation in social life are unusual. If there is a depressive appearance, mood swings or an increased potential for conflict, the observations should be discussed with a doctor.
Treatment & Therapy
Treatment of the Night blindness depends on the diagnosis. Unfortunately, if night blindness is congenital, no promising therapeutic method is known to date.
Damage to the fine vasculature of the eye and retina, e.g. B. by diabetes, can so far not be reversed.
When dietary vitamin A deficiency or gastrointestinal disease has triggered night blindness, the twilight visual disturbances usually stop when the underlying problem has been resolved.
You can find your medication here
➔ Medicines for visual disturbances and eye complaintsOutlook & forecast
Night blindness in itself does not lead to a reduction in life. However, the quality of life often suffers. Those affected find it much more difficult to find their way around in the dark. This can lead to a need for help, as the disappearance of sunlight is an everyday phenomenon.
Basically, the night blindness persists permanently after the first appearance. Most patients then experience neither improvement nor deterioration. There are limits to medicine so far. While a simple ametropia can easily be corrected with a visual aid, this is not the case with night blindness. In some cases, night blindness means that those affected cannot exercise certain professions.
There are better prospects for congenital inpatient night blindness. This form heals in many patients. Gradients in which a vitamin deficiency causes visual impairment can also be successfully treated. On the other hand, people with retinitis pigmentosa can expect a deterioration. Even blindness is possible.
The diagnosis of “post-blindness” therefore leads to a differentiated prognosis. While a shortened life expectancy is not foreseeable, there are usually lifelong restrictions in everyday life and at work. All in all, a mixed outlook can be formulated.
prevention
A prevention of Night blindness is usually impossible. Congenital forms of night blindness, such as rod weakness or retinopathia pigmentosa, cannot be prevented. In the case of diabetes, an adapted lifestyle and well-controlled blood sugar often help to avoid damage to the vascular system, including that of the retina. Vegetarians and vegans should be careful to eat vegetables that contain vitamin A, e.g. B. peppers, tomatoes and carrots.
Aftercare
The extent to which aftercare is necessary depends on the chances of recovery. Especially people who have suffered from night blindness since birth have to deal with the disease for a lifetime. There is no prospect of a cure. You have no choice but to seek help from others in the dark and to avoid dark surroundings as a matter of principle. Psychological support may be indicated selectively.
Cases in which night blindness arose in the course of life are usually different. Regular checks are then indicated. Because there is a risk that eyesight will deteriorate even further. An annual visit to the ophthalmologist prevents complications.
In addition to taking an anamnesis, an eye examination takes place in which the doctor determines the time it takes for the eyes to adapt to the darkness and the perceptible light intensity. Clear comparisons with the past can be drawn from this information and general determinations of visual acuity and field of vision. In this way, necessary treatments can be initiated in good time. The diagnosis of night blindness brings with it some requirements for the patient himself. The risk of injury in road traffic should not be underestimated with night blindness.
You can do that yourself
No home remedies are available to those who are night blind. Natural remedies like blueberry extracts are controversial. The additional intake of vitamin A is also only partially successful. Without a medical diagnosis, it is strongly advised not to self-medicate using alternative methods.
The reduced vision in poor light causes restrictions in everyday life. This has to be accepted and mastered. Depending on the severity of the symptoms, protective glasses with filters prevent those affected from feeling blinded by light. However, these glasses do not correct or improve eyesight. Anyone who suffers from real night blindness refrains from driving for the sake of themselves and others and makes use of public transport or driving services. Flashlights help with daily journeys in the dark. These ideally have a uniform cone of light to make it easier to see. Digital voice assistants, who explain the way via smartphone, help with orientation.
Self-help groups and associations support those affected. They offer advice on any question. Exchanging ideas with other people affected helps to overcome everyday hurdles. The self-help association Pro Retina is specifically aimed at people with retinal diseases and supports people who are affected by night blindness.
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