[TheForge] Vision damage and welding shields pt 2

[Bob Rackers]

Didymium is used to filter out a specific wavelength of light produced by
sodium glass.
If you don't work with sodium glass, there's no need for didymium lenses. None.
Polycarbonate lenses filter out virtually all UV, and welder shades filter out
IR (to different degrees depending upon the particular shade).

UVEX sells glasses which have safety glasses with flip-up welder shades which
filter out both UV and IR.

As a passing note, even glass workers who work with types of glass other than
sodium glass have no need for didymium glasses, since they don't have the
problem with "sodium flare".

But don't take my word for it. If you search hard enough you can find the
transmittance graphs on the net.

Bob