Hey guys, it's been a while! So for my story, I'm trying to figure out how I can create this Vampire-like character. His nickname is 'Vamp', he was a biological experiment for the U.S.S.R. in mid 1970's. They originally intended on putting him into capitalist nations to literally scare people. I'm having trouble with the science behind him. I want to know if there is a way (which I'm sure there is) of damaging the human eye to make it extremely sensitive to light, and easier to see things at night (the part I'm unsure of). Another thing, I want him to rely on foreign blood sources to survive, I'm wondering if there is any sort of human condition where the person dies off because of a lack of blood-cell reproduction; I want to give him that disease but make him prey on humans every few days to regain the blood source. Any help would be appreciated, I'm not sure how to Google those things because they're quite complex. If anyone has a hard time understanding what I said, just ask and I'll try to make it more clear! Thanks!