Ancestors of ancient Dwarfs who evolved their intelligence had created a famous staff, called visions' staff. Each blind Dwarf would undergo the test of using the staff, and the chosen one would have the vision back thanks to it. Legend has that a pair of eyes of a great warrior would bring normal vision, 2 pairs of eyes would bring besides the vision, their perception increased by 100%, 3 pairs of eyes could see other worlds and acquire knowledge outside the intelligence of the planet. The problem it that the staff doesn't accept any eye,
and if it doesn't, the Dwarf would have to continue searching.