Abstract: A protection shield, e.g., a welders mask, has an only slightly transparent screen such as a welder's glass movable in front of and away from an opening in the shield by a reversible electric motor, driving the screen directly. The screen is guided by rods in the shield, which it engages in only a few discrete points. Motor, screen and guides are easily removable from and insertable into the shield. This gives a simple and reliable structure with low energy requirement. There are provisions for charging a battery energizing the motor either by solar cells or by an external source. A hand operated switch is provided with means to be carried on a finger of the user, which switch operates the screen. A spatter glass is taken up in the shield in guides so as to be easily removable and replaceable and so that its thickness is not critical.