The Telegraph:

Darwin was baffled by it; Christians see it as evidence of the divine. Will science ever unlock the secrets of the human eye?
When the body of Dr Yoshiki Sasai, an eminent Japanese biologist, was discovered in August this year, his death was widely mourned across the world of science. Not just for the abrupt end to his glittering career  ………….

Sasai had grown an eye. And in doing so, he’d also helped resolve a scientific obsession that had lasted centuries.

In very basic form, the eye is thought to have first developed in animals around 550 million years ago. But such is its perfect design – its infinite adaptability, and irreducible complexity – that many argue it is proof of the divine itself. Even today, Christians and creationists believe that Charles Darwin himself was troubled by its existence – seizing upon an (oft-misquoted) aside in Origin of Species, where Darwin remarked that the whole idea of something so flawless “could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.”

Retina under electron microscope

The eye has become a focal point for biologists, ophthalmologists, physicists and many other branches of science ever since. So when the Spanish neuroscientist Santiago Ramón y Cajal made the first anatomical diagrams of neurons and the retina in 1900, it stoked a century of biologists attempting to unlock the eye’s secrets.

And there have been several discoveries. Unlike our ears and nose, for example, which never stop growing our entire lives, our eyes remain the same size from birth. Then there’s the complicated process of irrigation, lubrication, cleaning and protection that happens every time we blink – an average of 4,200,000 times a year.

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