5) Eye Prisms

In the 1950’s Theodor Paul Erismann created goggles that turned the world upside down. When you put them on, everything you see is inverted; simply moving about is tricky and catching a ball nigh on impossible, and you can forget aiming your wee stream with any accuracy. Erismann decided to make his long-suffering assistant Ivo Kohler wear them constantly for more than a week.

What he found was that within about eight days human brains adjust and no longer see the world as upside down, the upside down becomes normal. The weirdest bit about it was that once you took the glasses off, everything looked upside down again. Mammalian brains adjust and deal with whatever you throw at them.

Any way, what about the animals? Well, similar experiments have been tried on chickens and salamanders. Prisms were stuck onto chicken eyes so that everything they saw was 7 degrees to the left. Chicken brains can’t cope and never adjust. If you leave the prisms on their eyes they eventually die of starvation because whenever they peck for grain they are always 7 degrees the wrong side of it. Salamanders didn’t fare any better I’m afraid.