X-ray glasses do not actually allow the user to see through objects. They are constructed of a plast
X-ray glasses do not actually allow the user to see through objects. They are constructed of a plastic frame with lenses of heavy cardboard. In the center of each lens, small holes about 0.25 in (0.64 cm) in diameter are punched out. Feathers that create a polarizing effect cover the holes. When looking through the hole, objects appear to have a transparent outline and a solid center. This effect creates the illusion of x-ray vision. -- source link