St. Didymus, who is commemorated on October 18 (New Calendar), became blind at the age of four, headed the famous Catechetical School in Alexandria in the fourth century.
Here are two sites I have found in which St. Didymus the Blind is commemorated:
1. As recorded in The Prologue from Ohrid: Lives of Saints by Saint Nikolai Velimirovičor for the Old Calendar date October 18, and New Calendar date October 31:
“St. Anthony the Great greatly respected this wondrous blind saint who had the spirit of discernment. He stayed with him and prayed to God with him whenever he came to Alexandria from the desert.”
More sources on St. Didymus the Blind: