Guava. That depends on the type of eye drops you drink. Some types of eye drops contain tetrahydrozoline which can irritate the body's system and then cause diarrhea. Sometimes tetrahydrozoline in the eye drops will make blood pressure increased once it counteracts with some medications like blood/heart prescriptions. So drinking eye drops maight be a serious problem. If you drink eye drops by accident, you should go to see a doctor immediately.