I've heard that the black lights, at stores like Spencers Gifts that are black but have the purple light, are harmful to the eyes if you look into the bulb. Is that true or is it for different kinds of black lights or something?
Yes it can cause permanent blind spots
While black lights do produce light in the UV range, their spectrum is confined to the longwave UVA region. UVA is considered the safest of the three spectrums of UV light. It is more dangerous to pass an hour outside in the sun than to look at a black light for 12 hours. There are no health risks with black lights.
