What are the symptoms of night blindness

What is night blindness?

 

The light goes out and you can't see anything at first - so far, so normal. But if your eyes have not got used to the darkness even after a long time and you can barely see anything, you could be night blind. Cause is one Damage or destruction of the rodswho are responsible for twilight vision. Night blindness can be dangerous, especially when driving. If you have any suspicions, you should definitely see your ophthalmologist.

Real post-blindness vs. other vision disorders

Certain sensory cells in the eye are responsible for seeing at night - the rods. During the day, however, the cones ensure that you can see different colors. If it suddenly becomes dark or light, the eyes have to close first get used to the new lighting conditions. The pupils widen or narrow in order to adjust to the changed light conditions. Usually this only takes a few seconds or a few minutes. With increasing age, however, twilight vision deteriorates and the eyes take longer to get used to. Affected have one higher aperture sensitivity, but are not night blind.

Night myopia also differs from “real” night blindness - a short-sightedness that only manifests itself in the dark and can be corrected with glasses. In addition, eye diseases such as glaucoma or cataracts often affect twilight vision.

The causes of night blindness

Real night blindness can have various causes. What they all have in common is that they gradually destroy the chopsticks. The ability to see in the dark deteriorates or is completely lost. Known causes include:

  • congenital genetic diseases such as retinopathia pigmentosa, which usually occurs in adolescence or middle adulthood, later also attacks the cones and can thus lead to blindness
  • other hereditary retinal diseases such as Oguchi disease, congenital inpatient night blindness or liver amaurosis
  • Diabetes mellituswhich often attacks the retina and photoreceptor cells
  • Vitamin A deficiencywhich is very rare in industrialized countries

 

Common symptoms of night blindness

Night blindness manifests itself primarily in the fact that those affected see worse in the dark than before. There is no getting used to, visual acuity is reduced and outlines can only be perceived indistinctly. If the rods are completely destroyed, those affected can no longer see anything and are blind at night. Depending on the cause, other symptoms such as a restricted field of vision or eye tremors occur.

Get tested for night blindness

If you feel like you can't see well at night, you should make an appointment with the ophthalmologist. They will do a thorough check-up to see if you have night blindness. First he will ask you about known hereditary diseases in your family, followed by an examination of your eyes. The doctor measures the following values:

  • Visual acuity
  • Facial field
  • Color vision
  • Adjustment speed of the eye to the darkness (with the adaptometer)
  • Response of the photoreceptor cells to light stimuli (with the help of an electroretinogram)

 

In this way, the ophthalmologist determines the cause of the night blindness and takes appropriate action.

What to do in case of night blindness

A vitamin A deficiency rarely triggers night blindness in western regions of the world - in contrast, it is a common cause of blindness elsewhere. However, some intestinal diseases are associated with malnutrition. If this is the reason for the night blindness, it can be caused by the Administration of vitamin A. be treated.

For the other causes exist so far no mature therapy options yet. Even glasses cannot do anything against night blindness. However, research is so advanced that this may soon change. One helps in the early stages and with other impairments of twilight vision Night glasses with a yellowish tint in the process of reducing the glare from lights.