These are high specification safety goggles (not ski masks!) for use in industrial environments when greater protection than that afforded by simple safety specs is required. They conform to EN 166 with designations as follows:
Frame marking: EN166 349 BT CE, which indicates protection against liquids (droplets or sprays), large dust particles > 5 micron, molten metals and incandescent solid matter; resistance against medium energy impact (resists a 6 mm, 0.86 g ball at 120 m/s.).
Lens marking: 1 BT 9 CE, which indicates optical glass for continuous work; resistance against medium energy impact; resistance against high speed particles at extreme temperatures; non-adherence of molten metals and resistance to penetration by incandescent solid matter.
However, being goggles, they are not as convenient to use as ordinary safety specs. Fitting requires two hands. They fit comfortably over my prescription spectacles, though I do find that there is a distracting reflection of the spectacle frame in the goggle lens. Taking them off is more of a faff as the straps tend to entangle with the spectacle earpieces, but this is probably unavoidable.
The space behind the lens is ventilated to help prevent condensation and fogging, and the soft plastic layer that comes into contact with the skin is comfortable enough, though I have not had to wear them for long periods, yet.
These are essential items when circumstances dictate. As for value, it depends what price you put on your eyes.