Putting ear or eye drops or using nasal sprays for allergy or sinus problems does not nullify the fast, according to some scholars of Islam. There is nothing whatsoever in the sources to suggest that the Prophet (peace and blessings be upon him) ever considered any such activities as invalidating one’s fast.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: Traditionally, the activities you have mentioned above have been mostly considered as invalidating one’s fast. Some of these scholars, to one’s utter shock and disgust, even go so far as to advise people against relieving themselves for fear of ingesting water while purifying themselves (during the course of istinja’)! This is undoubtedly a glaring example of the hair-splitting that is characteristic of medieval fiqh, which we can readily dispense with as being utterly irrational.
Such rulings, moreover, have drawn harsh criticisms from scholars and jurists such as Ibn Taymiyah, Ibn Hazm, and others. They strongly and persuasively argue that there is no need to hold on to such rigid interpretations.
the last mentioned group of scholars do not consider any of the above activities as in any way affecting the validity of one’s fast. They have put forward the following reasons for their ruling:
1. None of the activities mentioned above amount to feeding or drinking, which we are told to abstain from by the clear texts of the Qur’an and the Sunnah.
2. If any of the above activities had been considered as invalidating the fast, then the Prophet (peace and blessings be upon him) would have plainly said so, for these are activities people are accustomed to doing most frequently.
There is nothing whatsoever in the sources to suggest that the Prophet (peace and blessings be upon him) ever considered any such activities as invalidating one’s fast. If they were meant to be, then why didn’t he say so? Didn’t the Prophet (peace and blessings be upon him) say that he has taught us everything we ought to do as an obligatory duty in our religion?
In light of the above, I conclude that there is no justification in considering the above-mentioned activities as breaking one’s fast. As has been rightly pointed out by Imam Ibn Hazm, these are not the methods human beings have been feeding themselves throughout the ages.
In conclusion, use of ear/nose/eye drops or nasal sprays does not invalidate one’s fast, and therefore one need not redo the fast, if one has had recourse to any of them while fasting.