Pigmenthártya
Pigmenthártya is a Hungarian term that translates to "pigment membrane" in English. It refers to a layer of tissue that contains pigment cells. This term is most commonly associated with the eye, specifically the iris and the choroid. In the context of the iris, the pigmenthártya is responsible for the color of the eye. The density and distribution of melanin pigment within this membrane determine whether eyes appear blue, green, brown, or other colors. Variations in pigmenthártya can lead to conditions like heterochromia, where a person has irises of different colors or different colored sections within the same iris. The choroid, another part of the eye, also contains pigmenthártya, which helps to absorb stray light and prevent scattering within the eyeball, thereby improving visual acuity. Beyond the eye, the term might occasionally be used in broader biological contexts to describe any pigmented tissue layer, though its specific application in ophthalmology is its most recognized usage. The scientific study of pigmenthártya involves understanding the cells that produce melanin and how their arrangement affects light absorption and reflection.