Didymus the Blind (alternatively spelled
Dedimus,
dedimu5 or
Didymous) (c. 313 – 398) was a
Christian theologian in the
Coptic Church of
Alexandria, whose famous
Catechetical School he led for about half a century. Despite his impaired vision, his memory was so powerful that he mastered
dialectics and geometry, subjects whose study usually benefits appreciably from sight.