It is narrated from Sayyidah Umm al-Hasan (may Allah be pleased with her): I saw Sayyidah Umm Salamah (may Allah be pleased with her), the honoured wife of the Prophet (peace and blessings be upon him), prostrating on a leather cushion because of an eye inflammation (ophthalmia) she had.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3674