Reposted at Lightlover's request from the original posting in the Warning Labels topic -- it's a long posting with a lot of URL links and a short quote from each source. See the originals for more information.
Short summary -- bright blue light can, with no pain or warning symptoms, damage your retina and blind you.
Blue light is 100x as dangerous as red light for eye damage.
Damage adds up over time. Ordinary daylight causes minor aging of the eyes; brighter light works much faster.
The brain "fills in" blind spots so your eye doctor may see a problem before you are able to notice anything is wrong. If you notice ANY vision problem get it checked.
If you notice a "curtain coming down" optical effect go to an emergency room immediately -- that may be a retina detatching, peeling off the back of the eye, and immediate laser surgery may be able to tack it in place and save your eyesight.
So says my opthalmologist, who sees me for early cataracts (started around age 30). What follows are results of a quick Google search.
I can't tell you what will hurt you. All I can say is -- you won't notice the damage, it's painless and cumulative.
If you are not now regularly getting a complete eye checkup with dilation of the pupils by a real eye doctor -- consider that should be a wise precaution for anyone.