Maliks Muwatta Book 29, Hadith Number 106.
Section : Limit of Abstaining from Adornment in Mourning.
Yahya related to me from Malik that he had heard that Salim ibn Abdullah and Sulayman ibn Yasar said that if a woman whose husband had died feared that an inflammation of her eyes might affect her sight or that some complaint might befall her, she should put kohl on and seek a remedy with kohl or some other cure even if it had perfume in it.
Malik said, “If there is a necessity, the deen of Allah is ease.”