Jami` at-Tirmidhi 726
جامع الترمذي#726Da'ifAnas bin Malik narrated that :a man came to the Prophet and said: "My eyes are bothering me, can I use Kuhl while I am fasting?" He said: "Yes
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirDaif Isnaad
Al-AlbaniDaif Isnaad
Bashar Awad MaaroufDaif
Zubair Ali ZaiDaif
In-book reference: 8:45