The illusion of super powers - X-ray specs

Often given away free in comics, X-ray specs supposedly give you superman's power of seeing through solid objects. They were a trick of course but the reality is actually far more interesting than the myth.

Making a spectacle of yourself

The glasses are normally a big colourful cardboard spectacle frame, the Ôlenses' of which are made with two layers of cardboard with a small hole in the middle. You look at the world through these holes, but unknown to you embedded in between the cardboard layers of the lenses, covering the holes is a bit of bird feather. It's the feather, with a bit of physics and the help of your brain that makes them 'work'!

Going feather into X-ray specs

The veins of a feather are semi-transparent and grow very tightly together. This ribbed structure is so dense that light coming in through the holes is diffracted. That is it's bent slightly by the structure of the feather veins. This causes the wearer to see two slightly displaced and blurry images of the world. Looking at a pencil for example you see two offset images. When your brain combines these together you get a darker image in the overlap. You interpret this as being able to see the graphite in the pencil or the bones in your hand. Well sort of.

Invisible fish anyone?

It was American mail order marketer Harold Nathan Braunhut who invented X-ray specs. He also 'invented' and sold invisible goldfish. These were non-existent fish that were guaranteed to remain invisible permanently, which was fairly transparent marketing ploy that you can see right through!