Definitely, we cannot directly look at welding. The strong light overwhelm our eyes ,it may cause eyesight losing or other problems.
Those machinists always wear masks to protect themselves. The special mask is made of special materials which can prevent the radiation and strong light.
For the people without any protection, it's better not to look at that, for our own sake.
And not only do the strong light and radiation are bad for eyes, but also do they harm our whole body. So stay away from the welding spot next time.
Yes, it is true that looking at welding is bad. It can even cause permanent damage to your eyes. Since the liight of welding is too bright. Your retina is highly focus on the light, so it is very easy to get your retina get hurt due to the strong light. So when you are doing welding, you must wear a mask.
It is bad for your eyes when you look at welding because of the strong fire with strong lights which will stimulate your eye nerves. You should just wear the goggles when you do the welding. Or else, your eyes may have the burning feeling after the welding. You could also do the warm compress after the welding to make your eyes feel comfortable.