Mine used to get really blood red, but then all of a sudden it stopped and now they get a bit yellowy and redish, but not bad enough to tell, just looks like i've been rubbing my eyes. I tell people i rode past a lorry on my paper round and it loads of dust came up, blinding me works every time! (I only tell people of they ask or if they can't know, but with my parents if it's going to be obvious i'm high i go in the room rubbing my eyes saying i have something in them lol