Yes, you'd better not use expired eye drops. If there use the eye drops, you may likely to get a batieria infection. manufactures usually will make them safe up to 3 to 6 months after. of course, this also depends on where you have them stored. If you keep your eye drops in cool and dry places, it may stored for a longer time. Anyway, you are strongly recommend to buy new eye drops instead.
Yes. Never use expired eye drops, or it will put your eyes at the risk of get contaminated. Once the eye drops are expired, it will develop many bacteria in them. If you use expired eye drops, you might get infection. As we all know, eyes are very delicate, we should try to avoid damaging them. Otherwise it will cause serious problems. You'd better throw your expired eye drops away and get another new one. Good luck!