When I beat my wings he sees a little.
Ōkagami, The Sixty-Seventh Reign (Emperor Sanjō) (p 82-83 of McCullough’s 1980 translation):
It was a great tragedy that this Emperor was troubled by failing vision after his abdication. His eyes looked normal, and iso it was hard to believe that he was blind. His eyeballs were as clear as anybody’s. Furthermore, there were times when he saw quite well. For instance, he once said, “I can see the cords on the bamboo blinds….”
His Majesty tried all kinds of ineffectual cures for his eyes. It was a sad case. In an effort to combat the nervous disorder from which he suffered so dreadfully, the doctors advised him to pour cold water over his head in midwinter. The icy deluge made him tremble violently and change color, and I have heard that the witnesses all felt great sympathy and distress. He was also taking medicine for his ailment—a potion called the elixir of immortality. Some people said, “Anyone who drinks the elixir of immortality is bound to develop that kind of eye trouble.”
But as a matter of fact, the blindness was cuased by the spirit of a Chaplain named Kanzan, who announced through a medium, “I sit on the former Emperor’s head and cover his eyes with with my wings. When I beat my wings, he sees a little.”
And so it is here.