If the drone does what it supposed to do then no problem. If the drone loses control or it hits your hand or arm and it sense something and flies the other way, you head and eyes are in trouble. But that's ok I guess, if it doesn't happen after a million times so what if million +1 it take out your left eye; at least you got a million launches in. It's called a freak accident and the further that drone is away from your face (not at arms length) when the blades are spinning, the better off you are. My lifestyle, I cannot afford such an injury just messing around with drone trying to show off (which I consider hand-launching or hand-landing to be when it is not absolutely necessary); my opinion.