Does an eye drop break the fast if its bitter taste reaches the throat? And what is the ruling if I use it during the day and then fall asleep, and I don't know whether I swallowed it or not?

Scholars have differed regarding eye drops, whether they invalidate the fast of a fasting person or not. Sheikh al-Islam Ibn Taymiyyah and Sheikh Ibn Uthaymeen chose the opinion that they do not invalidate the fast, even if their taste reaches the throat, because they are not considered food or drink.