Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.134.
Section : Fasting, applying kohl or eye-drops or anything else to the eyes.
These acts are all permissible, even if some taste from it finds its way to the throat, as the eyes are not a passageway to the stomach. Anas reported that he would apply kohl while he was fasting. This is the opinion of the Shaf’iyyah. Ibn al-Munzhir records the same opinion from ‘Ata, al-Hassan, an-Nakha’i, al-Au~a’i, Abu Hanifah, Abu Thaur, and Dawud. It is related from the following companions: Ibn ‘Umar, Anas, and Ibn Abu ‘Aufa. According to atTirmizhi, nothing authentic has been related from the Prophet concerning this question.