There exists a book that I have not read in years. In said book, the main character discovers they have deadly powers associated with their vision, and that since they are hard to control they must wear a blindfold for years. Their friend has animal taming powers, their father has the same power, and the setting appears to be medieval with serfs and farms.
At the end of the book, we learn that
He was lied to and his powers were wimpy, and he gazes upon his mother when she is on her deathbed.