Reference: Fataawa Ramadhaan – Volume 2, Page 510, Fatwa No.472
Majmoo’ Fataawa Shaykh Ibn Baaz – Volume 3, Page 248
Question: Does the application of [eye] drops during the day in Ramadhaan break the fast or not?
Response: The correct opinion is that [the application of eye] drops do[es] not break the fast, even though their is a difference of opinion amongst the people of knowledge – where some of them have said: If its taste reaches the throat, then indeed the fast is broken. [Nevertheless], the correct opinion is that it categorically does not break the fast because the eyes are not an inlet [for food and nourishment].
However, to be on the safe side, if he was to make up [the fast for this day] so as to remove himself from any [doubt over the] difference of opinion [amongst the scholars] over whoever finds its taste in his throat, then there is no harm [in him doing so], otherwise, that which is correct is that it does not break the fast whether it is [applied] in the eye[s] or the ear[s].