Would Looking At Black Hole Blind You?

 Black holes are something huge and dangerous you want to stay away from. 

If it is naked without anything falling into it, all it will do is make a lensing effect of the light of what is behind it. In this situation, no damage to the eyes would occur. 

However, if the black hole still has an accretion disk, then stuffs would be differ. As matter spiral down the disk toward the black hole, the rotational speed increases gradually to relativistic values that - with gravitational compression - results to very high temperature, thus making electromagnetic radiation all over the spectrum, with X-rays. Depending on the intensity of light, you'd be doomed...