These are toy products that use a simple optical illusion. They typically feature a tiny feather or diffraction grating between layers of cardboard, which blurs the edges of objects and creates a double image. This gives the faint impression of seeing "bones" in your hand, but it does not work on clothing.

Modern online ads often use misleading video editing or fake technology names like "Josephida" or "penetrating glasses" to sell regular cheap sunglasses.

Advertisements for glasses that claim to "see through clothes" are almost universally . While the idea has existed as a novelty prank since the early 20th century, no commercially available consumer glasses can actually see through solid fabric to reveal skin in the way these ads suggest. The Reality of "X-Ray" Glasses