Not trolling, just stating that we're used to the sun (150,000 some odd years of evolution) and it projects higher amounts of radiation in a broader spectrum than blue LED's. I'm reasonably confident that no one has gone blind from small amounts of exposure to the sun, so my thoughts were that being exposed to blue LED's at small intervals would have equally minimal effects. There are quite a few articles that do support the idea that long exposure to blue LED's is harmful, but they seem to be specifically concerning computer monitors, and TV's, etc.
If you're out in the sun all day, or for longer than 10-15 mins you should probably have eye protection on likewise in a grow tent. It's just common sense.