Complex sentence: In 1922 he contracted an eye disease that eventually left him completely blind, which caused him to rely increasingly on his students, including René Wellek and Bohumil Trnka, to assist him in his teaching, reading, and writing.
Split into simpler sentences: In 1922 he contracted an eye disease that eventually left him completely blind. This caused him to rely increasingly on his students, including René Wellek and Bohumil Trnka, to assist him in his teaching, reading, and writing.