It is narrated from Sayyidah Aishah (may Allah be pleased with her) that Ibn Umm Maktum (may Allah be pleased with him) was a muezzin of the Messenger of Allah (peace and blessings be upon him), and he was blind.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2004