Looking for this bl I once read but can't remember the title for the life of me

It's about this super famous author who turns out to be a serial killer and this guy (the bottom dude) witnesses this murder but pretends to be blind so he can escape this killer (the top) and the killer author basically tests him to see if he's actually blind by doing fucked up shit and watching his reactions. It's psychological horror I think but when I check the tags I can't find it :( pls help I think it was smt with "blind"