The modern age of x-ray vision kicked off in the 1930s, though maybe not where you think. The Lady With the X-Ray Eyes, an absurdist novel by Bulgarian writer Svetoslav Minkov was published in Germany in 1934. Here, a young woman suffering strabismus is treated by a surgeon who somehow also gives her the ability to see through assorted materials, including — naturally — the human body. Using this device, Minkov was able to critique the superficial nature of modern society. (The Man With the X-Ray Eyes followed in 1963, albeit in the form of a low-budget movie directed by Roger Corman. It’s worth noting that the ending of this movie is similar to that of the 1896 story “Le Rayon X,” by French writer Charles Recolin.) The more important development, of course, came in April 1939, on page 51 of Action Comics #11. Superman — the prototypical comic book superhero who is today still fighting for truth, justice and the American way — first appeared in Action Comics #1, but it wasn’t until this issue that x-ray vision was added to his list of superpowers. The plot involves a pair of brokers who are trying to bilk investors in an oil well. Superman, disguised as businessman Homer Ramsey, intervenes. And when the brokers hire a couple of thugs to take care of him (“Our rates has risen t’ 500 smackers per,” the latter inform them), Superman watches and listens from a nearby rooftop using his “x-ray eyesight and super-acute hearing.” X-ray vision remains one of Superman’s signature superpowers. In all these years, though, he has generally resisted the temptation to use it to see through people’s clothes. He is, after all, a comic book superhero, bound by a strict code of honor; employing such a power for anything but an altruistic purpose would be unthinkable. Comic book readers, of course, are a different story. In the 1950s, ads for a range of novelty items — including the wildly popular X-ray Specs, which again evoked the idea of x-rays to appeal to the more prurient interests — started appearing in the back pages of comic books. (Several companies offered X-ray themed glasses, but X-Ray Specs came courtesy of the Lynbrook, N.Y.-based Honor House Products; founded by Edwin Wegman in 1951, the company stayed in the novelty item game until the mid-1980s, when most novelty mail-order shops succumbed to the rising price of postage and comic books.). X-Ray Specs were really anything but — the light-refracting effect was achieved by placing bird feathers between two pieces of cardboard with holes poked in them — but carefully worded ad copy and a titillating image or two convinced adolescent readers that they might just be able to use them see through people’s clothes. Several generations of readers grew up with ads for X-Ray Specs, so it’s no surprise that we still often associate x-ray vision with a leering desire to see people naked. For an example, look no farther than the controversy that erupted in 2010 over the introduction of backscatter x-ray technology in airport security lines (See: An End to 'Virtual Strip Searches' With Whole-Body Scanning?). The technology reveals precise anatomical details of travelers passing through security, leading countless journalists and commentators to dust off the “x-ray vision” description. Travelers and privacy groups alike expressed concern over the introduction of backscatter x-ray systems in airport security lines. (Image: TSA) The first article to come up in a Google search: “X-ray vision for TSA,” from the website American Police Beat. “The devices make the dream of every eighth-grade schoolboy a reality,” the article explains. “The machines essentially look through clothing for hidden weapons, and the images are pretty spectacular.” More recently, X-ray vision has been enjoying a bit of respectability. With the announcement early this year of a device that could detect and control terahertz radiation using optics and material science — and thus “see” through a range of solid materials — writers once again turned to the x-ray vision trope. This time, though, they noted the positive potential applications of the technology, including advances in medical scanners, communications devices and chemical detectors. To read Part I of this blog, see: The (Sometimes Sordid) History of X-ray Vision, Part 1