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Spectacles with a common type of plastic lens could record a wearer’s
exposure to hazardous radon gas. Allyl-diglycol carbonate, or CR-39, is the same
plastic the nuclear industry uses for its badge-style dosimeters. Robert
Fleischer, a geologist at Union College in Schenectady, New York, says that
alpha particles released by decaying radon leave tracks in the lens carbonate
that measure the wearer’s cumulative exposure over a few years. Checking the
lenses for radon exposure would be more accurate than measuring radon levels in
household basements, because you have no idea of how long people spend
there.