drink lots of water OR if your parents question your eyes look away and say in a soft voice "I was crying". They wont question it
my friend told me rubbing them a little helps...lol or u can say a gust of wind blew something (dirt) into ur eyes and u cant get it out so uve been rubbing ur eyes alot
Rubbing them will make them more red because they are being agitated. You could always splash some water on your face because this will also take away some redness in your face if you get that way when you are high (my cheeks get pretty rosy).
constantly bring around a can of redbull and say that your just really high on caffeine. it also works if you get a bit twitchy.
^ Are you thinking of smell. I know that smoke has an effect on some people in a way that it agitates their eyes, but I don't know.
rubbing your eyes and acting like you've been crying helps. Thats what i used to do, now since i met my bf he always has it because of his parents and job so we just use that. We never buy it though we always steal it because its to expensive.