Shama-il Tirmidhi Chapter 007, Hadith Number 001 (048).

Ibn 'Abbaas Radiyallahu 'Anhu says: "Rasulullah Sallallahu 'Alayhi Wasallam said: 'Use kuhl made of ithmid on the eye; it brightens the eyesight, and strengthens and increases the growth of the eye lashes'. (Sayyidina Ibn'Abbaas Radiyallahu'Anhu also used to say) 'Rasulullah Sallallahu 'Alayhi Wasallarn had a small container for keeping kuhl, from which he applied kuhl in each eye three times every night"'.

Commentary.
Ithmid is a special type of kuhl which is reddish black in colour. It is obtained in the Eastern countries. Some of the learned say it is the Isfahaani kuhl, and other say it is the Totiya. Some 'ulama say, it means those who have good eyesight and it should be used by those with whose eyesight it agrees, otherwise a sick person's eyes will pain more by its use. It is more beneficial to apply kuhl at the time of sleeping as it will remain longer in the eyes, and will penetrate more into the pores. There are different narrations on the number of times it should be applied in each eye. In a few it is stated that it should be applied three times in each eye, as mentioned above. In other narrations it is stated that it should be put three times in the right eye and two times in the left eye. It is supposed that the variations are because of the different times of the narrations. At a certain time, Sayyidina Rasulullah Sallallahu alayhi Wasallam applied it in one manner and at another time in the other manner. Haafiz Ibn Hajar, Mulla 'Ali Qaari and other 'ulama have preferred the first method (as given in the hadith under discussion). the first method has been narrated many times from Sayyidina Rasulullah Sallallahu' Alayhi Wasallam, as will be seen in the narration that follow.