When John Milton wrote his most famous poem , Paradise Lost, he was completely blind. He had to dictate the whole thing, which is as long as a novel. Talk about patience (Source).
After he went blind, Milton made his daughters read to him in Greek, Latin, and other languages they did not understand. They eventually got into a domestic squabble about this, and Milton claimed they were being "undutiful" and "unkind." Now that's a demanding dad (Source).
In the 1640s, Milton was heavily involved in radical politics. He even wrote a pamphlet defending regicide (the killing of the king). Yikes (Source).