Is it really that difficult

At most places I have worked, I get a comment from fellow employees, and they this, "Dude, are you high?". I say, "No, why?" "Are you sure, because your eyes are blood shot". I have to explain to them everytime that its my contact lenses that make my eyes blood shot when I am up late. I guess they just throw out all other excuses for blood shot eyes and just think I was doing pot. I just feel like there are plenty of other reasons for blood shot eyes that people should be aware of. I probably get more comments like that than I get jokes about my name.