I am surprised that I can't find evidence of consumer gold foil sunglasses. Are the optical properties really terrible for day-to-day use? I'd think they'd be pretty sharp looking, and the cost of the gold shouldn't be prohibitive.
Most sunglasses are intended to reflect or absorb UV. As you can see in the OP, gold is only good at absorbing IR, which the atmosphere (and clouds and trees) do a decent job of absorbing when we are at ground-level. The gold would be more style than function for non-astronautical activities.
