Protection from light-rays by cold-weather goggles

To arrive at transmittance standards for cold-weather goggles, the levels of natural radiation were estimated, and the amounts by which they must be reduced to fall below the damage thresholds for various bands of electromagnetic radiation were calculated. No more than 16% of UV from 320 to 40 nm, and no more than 5% of UV from 290 to 320 nm should be transmitted. If the short wavelengths of the visible spectrum (less than 500 nm) are filtered out, the remaining wavelengths appear to pose no danger. Measurements of the transmittances of a random selection of 13 commercial skigoggles showed that most offer satisfactory protection.