Praise be to Allah.
The Standing Committee for Academic Research and Issuing Fatwas said:
“If a person applies kohl during the day in Ramadan whilst fasting, that does not invalidate the fast, but if he feels a trace of it in his throat then to be on the safe side he should make up that fast. It is better not to use kohl during the day when fasting.
And Allah is the Source of strength. May Allah send blessings and peace upon our Prophet Muhammad and upon his family and Companions.” (Fatawa al-Lajnah al-Daimah, 10/253)