Can prolonged bright light shined into the eye cause hyperpigmentation of the retina and the choroidal? If so does the hyperpigmentation all so effect pigmentnts in the iris?
No it cannot, exposed light not effect pigmentation of retina, choroid, iris. Prolonged sun exposure can cause pigment in macula and increase risk of macular degeneration. It can also change the pigmentation of the skin.
It's all the same layer called the uvea. So if one layer has more pigment unusually so do the others. Example brown eyes usually darkly pigmented retina/choroid blue eyes less pigment
It doesn't cause it it's all one process. Like dark skin and dark hair and dark brown eyes. Blond hair, fair skin and blue eyes. There are several ways hyperpigmentation can be used one is general color, another is a freckle (nevus) another is retinal pigmented epithelium hyperplasia.