The human eye was once considered so complicated and well-designed that it posed a problem for evolutionary biology — and an opportunity for creationists. How could something so useful evolve from random genetic mutations? Creationists took advantage of the conundrum of eye evolution, posing it as an example of something that, they claimed, must have been made by a higher power — or at least steered by one, which is the crux of the pseudoscientific idea of intelligent design. To this day, an online search for "eye evolution" yields multiple results from religious groups trying to muddy the scientific waters.
Yet to Mother Nature, the evolution of the eye isn't really a difficult feat at all, it turns out. Indeed, there are about 10 different types of eye design in the animal kingdom, and eyes have evolved independently across animal species approximately 50 times or more. Furthermore, genetic evidence reveals that eyes can evolve relatively quickly — in as short as just a few hundred thousand years. That may sound like a long time, but on geological timescales, it's a blink of an … well, you know.
