Isaac Newton seemed utterly unconcerned for any negative effects of any experiments he might try. He once stared directly at the sun for as long as he could stand it, just to see what would happen. He had to spend some days in darkened rooms afterwards in order to recover. Another time, he inserted a long knitting needle between his eyeball and the bone, and, using it, pressed down upon his eyeball, distorting its shape, in order to see what the effect upon his vision would be. Shockingly, he escaped permanent damage both times.