The Sellstrom cobalt blue flyer... the lenses pictured look a green-blue colour to me. I thought the traditional cobalt blue lenses were actually blue? Heading more into general rambling territory...
as i understand it green lenses are naturally good at blocking/absorbing light from the red end of the spectrum. Maybe one of the reasons green is the traditional colour for welding lenses?
Amber/yellow lenses are naturally good at blocking light from the blue end of the spectrum. They improve contrast and detail on overcast days snowboarding, cycling etc because light from the blue end of the spectrum scatters more easily making details harder to pick out. Blue lenses block yellow light which is obviously handy when fluxes or something else is producing a yellow - orange glare
I'm thinking (alright, guessing
) that modern materials and lens coatings may change things a lot regarding protection from IR and UV i.e. things like the warnings about cobalt lenses
probably only apply to the origional flavour/old stock etc?
I've no idea whether these are any good from an optical clarity perspective or with regards to IR as they only mention that the oxy fuel glasses don't provide enough UV protection for plasma cutting but FWIW...
http://www.plasmatech.co.uk/page/safety-glasses They are cheap but then cheap is no good if you can't see what you're doing properly and/or aren't protected properly
There's a crude non-quantitive way of testing for IR along the same lines as Jack's comments about polycarbonate and UV... TV remote 'light' can be seen by digital cameras for example. The same TV remote will also switch my Speedglas to it's dark state while sunlight/light bulbs/strip lights don't. Bizarrely it also reacts to LCD screens