What is night blindness?

Night blindness (nyctalopia) is the inability to adjust vision to darkness. People who have this anomaly, although they can see well during the day and in good lighting, at night or in low-light conditions they see worse or do not see at all.

Causes of occurrence

Night blindness belongs to the group of hereditary diseases of the retina (retinal dystrophy). Sticks are primarily affected, ie. photoreceptors that are responsible for night vision as well as peripheral vision (which enables navigation in space). In addition, there is damage to the pigment epithelium of the retina.

Night blindness also occurs as a symptom of several eye diseases, and is often associated with cataracts and glaucoma. It can occur with myopia, but also due to vitamin A deficiency.

Symptoms

The first symptoms of the disease appear in the period from 10 to 30 years of age and can be: impaired vision at night, difficulty navigating in the dark, inability to adapt to darkness when moving from bright to darkened conditions, progressive loss of peripheral vision (of which people are often unaware). Over time, visual acuity declines, which is in accordance with the degree of progression of the disease.

Diagnosis

This disease can only be determined by an ophthalmologist by examining the fundus, determining the width of the visual field, examining adaptation to the dark (adaptometry and perimetry) and electroretinography (which shows a changed electrical response of the retina to a light stimulus – reduced amplitude, when the changes in the fundus are minimal).  

Treatment

Unfortunately, there are no major advances in the treatment of night blindness. Although the disease cannot be completely cured, it is imperative to consult an ophthalmologist, because if the disease progresses, it can cause other complications, serious for vision.

It is recommended to use vitamins A and C, lutein, as well as wearing sunglasses with UV protection.

Night blindness in children

In children, night blindness manifests itself around the age of ten, with a gradual decrease in vision and a narrowing of the field of vision. If the disease occurs in association with more serious eye diseases, complete blindness may occur. Parents should monitor the development of their children’s vision and contact an ophthalmologist in case of any signs of poor adaptation of the child to reduced light. Also, taking into account the hereditary factor, children should be taken for examination even if they do not show any signs, but parents or close relatives have this disease.