You can get some burned powder in your face when you shoot straight up. It may be burned but it still isn't something you want in your eyes. But, anytime you are shooting a muzzleloading rifle, you should be wearing some kind of protective glasses. If you don't get an ignition of your pan charge, you will get a facefull of powder. Again, you will need safety glasses to keep the unburned powder out of your eyes. As long as the burned powder is not still hot, it will not likely hurt your eyes but it can be pretty darned uncomfortable. Unburned powder will not hurt your eyes but it, too, can be uncomfortable. Wear the safety glasses and you will have nothing to worry about.