Well, in my opinion, it is possible for you to have blindness because of looking at a light bulb. And what your mother told you is kind of no sense. But on the other hand, you are not supposed to look at the light bulb for a long time, or it will do some damage to your eyes. Generally speaking, a light bulb can give much harmful rays. And if you look at it for a long time, it will just affect your eye balls, leading to damage in your eyes. What is serious is that it may make your eyes feel pain. And sometimes, blurred vision, double vision, even photophobia can be possible too. Anyway, just be careful about it.
Yes, in some cases the light given out by the bulb can do some damage to your eyes. For example, some bulbs are daubed with fluorescent powders which can gives away many ultraviolet rays or infrared rays so as to do harm to your eyes. If people often read or work under or stare at these bulbs continuously for a long time, they will easily get fatigue eyes, dizzy eyes, watering eyes, dry eyes and so on. Even worse, people may get muddy crystalline lenses which can lead to cataracts. Therefore, you should not always stare at the light bulbs when they are on. Usually take time to look at distant objects and do some eye exercises regularly.