Used my L2D as a auxiliary work light tonight, had the welders gun in one hand and the light in the other,while steadying the gun tip with that hand, it put the light about 3” to 4” from the weld… Flux core non gas shielded wire feed welders spatter a LOT…. 
Those spots are metal, embeded in the lens…
Alaskan, Adventurer, Engineer. 