Photophobia

An aversion to light or photophobia is a hypersensitivity of the eyes to light. You can illness or in some animals physiologically occur. Affected organisms like looking at dark rooms.

Diseases

Typically, photophobia may be a symptom of various neurological disease states in the wake of such a migraine or meningitis and ophthalmological diseases, such as aphakia ( Linsenlosigkeit ), conjunctivitis any cause and other inflammations in the eye area, such as an iridocyclitis occur. In addition, a photophobia of the infant, a diagnostic sign of a congenital glaucoma. Also, albinos often show pronounced photophobia. Furthermore, a defect in the enzyme tyrosine aminotransferase (TAT ) are present ( Hypertyrosinämie / Tyrosinosis type II). Tyrosine is required tyrosine and phenylalanine in the degradation of amino acids.

Physiologically in animals

Many animals such as cockroaches and millipedes are permanent photophobia and thus mostly crepuscular or nocturnal. In some animals occurs photophobia only during certain phases, such as the wood tick (Ixodes ricinus) after the blood meal, so he avoids sunlight.

Parasitosis

Photophobia may be in some host animals affected by parasitism. For example, the amphipod Gammarus pulex causes of infestation by the worm scratch Pomphorhynchus laevis that the amphipod is less sensitive to light. He is easier fish to the victim. After the change of host, the parasite can develop, leading to Acanthocephalose of fish.