This is more of a caution but if you weld a lot and use a auto-darkening helmet obviously make sure it functions properly before using but also check the front of the shield to make sure that the sensors are clear of spatter or anything that can block them.
If there is something obstructing the sensor it will delay the helmet from darkening fast enough and you can get flash burn through the lens.
If there is something obstructing the sensor it will delay the helmet from darkening fast enough and you can get flash burn through the lens.