Aftermarket modifications

I assume by "eyelid" you may mean visors .I think visors were added to cut down on glare ,which could prevent crews from opposing trains from reading the engine number or other signal aspects . Recessed lenses may have also helped focus the the beam . Sometime around WW I the ICC required railroads to switch from acetylene or carbide to electic headlights . A number of railroads ,in a rush to comply,
including the C&S and D&RG, bought aftermarket kits for conveting o lder headlights to electric .The kit consisted of electical sockets an d connections , and nickel-plated patches to cover the glass chimney holes Hence , box headlights and chimneyed lights persisted on the D&RGW/RGS systems till the early 1940s . Incidentally ,Mike, there was one other manufacturer- Locolite .