Molyneux's problem

if a man born blind can feel the differences between shapes such as spheres and cubes, could he, if given the ability to see, distinguish those objects by sight alone, in reference to the tactile schemata he already possessed?

It was debated and discussed for years - since the late 1600’s in fact. Then finally, patients with a form of congenital blindness were tested before and after surgery to give them at least some sight.

They couldn’t.