You do know that you have a natural lens in the front of your eye, don't you?
Did you know that most all of your detailed vision is generated from a tiny spot called the fovea where your center of vision is?
Have you ever held a magnifying glass on a sunny day and burned something on the ground?
You would not hold that magnifying glass to the sun and look into it would you?
If you shine that green laser onto the ground on a sunny day you can still see the dot, that's because it's energy density is higher than the sun per that area.
Well with a laser the focused energy density is very concentrated into a small spot, if it were to enter your eye at arms reach it could easily destroy your most detailed vision in an instant and medical science has not yet perfected stem cell therapy to the point where anyone can readily benefit from it, meaning your little brother could blind himself with your "gift".
It's not a joke, the amount of concentrated energy is much more dangerous to your retina that it looks shown onto the ground.