There are quite a few ways to injure the eyes. They are such a delicate part of the body that even something seemingly minor can end up causing a lot of trouble. Then, there are some activities that beg for trouble if the proper precautions aren't taken. Like AirSoft.
AirSoft is like paintball in the sense that enthusiasts play games of tag with realistic guns, however, the ammo is plastic pellets not unlike BBs. The AirSoft guns are relatively inexpensive for basic models so it wasn't too long for a dedicated following to emerge. Without proper precautions, AirSoft can be a dangerous game of how fast can you shoot an eye out. That means that people concerned about eye care sprout new grey hairs.
Just like a Dentist would caution against eating candy and brushing your teeth after each sweet treat, Optometrists and Ophthalmologist will caution against playing this sport/hobby all together. If you do, make sure to get all the proper equipment that will have the greatest chance of keeping your eyes safe and healthy. Anything that seems to cut corners like Mesh Masks can still get debris through to the eyes and put your vision at risk.