Abstract: A surgical mask is provided with a vapor barrier for preventing clouding or fogging of optical aids or devices used by the wearer of the mask. The vapor barrier comprises a contoured strip of elongated soft closed cell foam material interposed between the upper edge of the mask and the wearer's face. The interposed material contours itself to and sufficiently extends over the wearer's face to form a seal and vapor barrier preventing fluid vapor exhausted from the wearer's nose and mouth from contacting spectacles, optical loupes or other optical instruments worn by the wearer and susceptible to clouding or fogging.