The FDA requires warning labels to be placed on laser pointers including it's classification and instructions telling users to not look directly into the beam. Unfortunately, there are now reports of lasers being imported from China and Russia that are not properly labeled. These lasers are significantly more dangerous and contain a green beam rather than a red one. Before buying a laser pointer, be sure to check that it contains a FDA warning label. Some potential effects of laser exposure are glare, flashblindness, and afterimage.
Glare is partial or complete loss of visibility while being exposed.
Flashblindness is an effect similar to looking directly at a flash while having a picture taken. These effects can last anywhere from seconds to days. Many safety professionals are more worried about the secondary effects of laser exposure. One researcher found that many eye injuries occurred when the people responded to being exposed in the eye by vigorously rubbing their eyes or sticking their fingers in their eyes. Never shine a laser pointer at anyone.