Shaikh Abbas Qummi (ra) narrated the following event from his father, telling us:
My father, Mohaddes Qumi was suffering from a severe eye-ache. The Iraqi physicians were unable to cure him.
One day, he asked my mother to take him the book called Usul Kafi. She gave it to my father.
My father said: the writer of this book, Kulayni, was one of the most pious men of his day and his book is a source of miraculous, spiritual events. It could not be ineffective.
He rubbed the book on his eyes once or twice. Two hours later, there was no sign of the pain.
THE WAYS OF THE RIGHTEOUS by Shaikh Jaffer Ladak