Answer
It was the Sunnah of Rasulullah (Sallallaahu Alayhi Wasallam) to apply Surmah every night in both eyes.
Rasulullah (Sallallaahu Alayhi Wasallam) advised, ?Use Ismid (antimony) as that grows the eyelashes and improves the sight.? (Bukhari)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai