Abu az-Zahiriyyah narrated: “I went to Tarsus, so I entered upon Abu Mu’awiyah al-Aswad after he had become blind. In his house, I saw a Mushaf (copy of the Qur`an) hanging from the wall, so I said to him: “May Allah have Mercy upon you! A Mushaf while you cannot even see?”
He replied: “My brother, will you keep a secret for me until the day I die?”
I said: “Yes.” Then, he said to me: “Verily, when I want to read from the Qur’an, my eyesight comes back to me.”
Abu Hamzah Nasir bin al-Faraj al-Aslami – and he was a servant of Abu Mu’awiyah al-Aswad – narrates something similar: “Abu Mu’awiyah had lost his eyesight.
So, if he wished to read from the Qur’an, he would grab around the room for the Mushaf until he would find it.
As soon as he would open it, Allah would return his eyesight to him. As soon as he closed it, his eyesight would leave him.”
[‘Sifat as-Safwah’; 2/413-414]