Night blindness
| Classification according to ICD-10 | |
|---|---|
| H53.6 | Night blindness |
| E50.5 | Vitamin A deficiency with night blindness |
| ICD-10 online (WHO version 2019) | |
As night blindness (colloquially), Greek. Nyctalopia , in medicine also hemeralopia , the restriction is the vision in dim light , respectively. The foreign words hemeralopia (from the Greek ἡμέρα “day” and ὤψ “eye”) and nyctalopia (from the Greek νύξ “night”) are both (contradictingly) used for both night blindness ( i.e. day vision) and day blindness ( i.e. night vision) and should be loud DIN 5340-207 can no longer be used.
Night blindness is a partially functional visual impairment .
The ability of the eye to adapt to the darkness is either limited or completely failed.
Night blindness results from a malfunction or the complete failure of the rods . If the rods fail completely, one speaks in the narrower sense of "night blindness". Seeing in the twilight is severely impaired. Seeing is practically impossible in an unlit night environment.
Night blindness can be a congenital defect or an acquired visual impairment. Innate forms (called "essential") are e.g. B. Oguchi syndrome (mutation in the gene coding for S-arrestin ) or the autosomal dominant inherited type Nougaret . As an acquired visual impairment, night blindness can e.g. As by vitamin A deficiency or other disease of the eye caused.
If there is a vitamin A deficiency , not enough rhodopsin (visual purple) can be formed in the rods , which is formed from the vitamin A derivative retinal and the protein opsin .
Night blindness can also indicate the onset of retinopathia pigmentosa .
Individual evidence
- ^ Dictionary of Optometry - DOZ Verlag
- ↑ night blindness. In: Online Mendelian Inheritance in Man . (English).
- ↑ Ludwig Weissbecker: A-avitaminosis (night blindness, keratomalacia, xerophthalmia). In: Ludwig Heilmeyer (ed.): Textbook of internal medicine. Springer-Verlag, Berlin / Göttingen / Heidelberg 1955; 2nd edition ibid 1961, p. 1984 f.
