@AlphaBeta
Ok on the skydiving/ shark idea, the psoriasis patient will not be paying attention to their skin, but to the shark or rapidly approaching ground.. a complete diversion of the senses. The 'hppd' sufferer will be fully using their eyes the whole time, the very organ that is the source of their perceived issue. It's completely different. If 'hppd' was real then surely they would see it more under such circumstances?
Here are some choice quotes from your posting history:
'My eyes water sometimes when visuals get strong, but there is no pain'...
sure you ain't got the visuals cos your eyes are watering? Why would your eyes water if you had visuals due to brain damage? Sounds like you are doing the same thing as I do to bring on 'hppd' visuals at will. Eyes glaze over, dont blink, eyes get a bit watery, low and behold I get visual snow, floaters, after images, the works.
'Sometimes I see a rainbow-like ring around white lights'...... so does every one else in this world, its caused by refraction of light by your eye lenses. Stare at the light and your eyes water a bit, refraction increases due to the tear and you get more rainbow. Reading this has actually made me remember how I used to get the same effect after swimming as a kid, due to watery eyes from the chlorine in the pool!
I think I may have upset you because I am implying that all this is your fault. It isn't. I think you are doing all this stuff subconsciously, that is the mind loop / trap that I describe in full effect.
You are I think a classic case of the theory, give me a full list of all your symptoms and I will explain them all with simple physical explanations, go on...