Important Notice: Our web hosting provider recently started charging us for additional visits, which was unexpected. In response, we're seeking donations. Depending on the situation, we may explore different monetization options for our Community and Expert Contributors. It's crucial to provide more returns for their expertise and offer more Expert Validated Answers or AI Validated Answers. Learn more about our hosting issue here.
There are a few theories on this. Some people believe that even in very dark conditions, light still penetrates the eyelids, which makes the patterns of blood flow visible. This is interpreted by the brain as geometrical patterns and objects. Dream images (explained by Freud) or spontaneous memories will later join in.
