Powerful lasers can be scary, especially if they're in the infrared. The first warning you receive that it's reflecting into your eye is blood seeping into the vitreous humor from your retina's capillaries.
I met one person who took a hit from a pulsed laser (the -other- Nobel from today). Pulsed lasers can be even worse. Fortunately, it was in his peripheral vision. But he described hearing and feeling the pop.
My undergraduate advisor had a small hole in his retina due to a high-power laser. The injury would have been far worse if it weren't a visible laser, since his blink reflex greatly reduced the damage.
