The case for… Varifocals

An old thought-experiment, but illuminating. Imagine you were able to go back to the time of the Neanderthals. Your bag only has room for a box of matches and a pair of varifocals. In our era, you are a confusing, vulnerable presence. In theirs, you are a god. Imagine the tribal elder, as you strap the spectacles to their blind head. Actually, they were proficient hunters, and the elder would have been about 37, with a screen time of zero, so probably had sharper eyesight. They might kill you. Bad example. They’d love the zipper on the bag, though.

Bifocals are impressive: a thin line separating different prescriptions, so one pair of glasses can do the job of two (or four monocles). Varifocals have no boundary. Invisible graduations allowing the wearer to see clearly at several distances. If David Attenborough told you this is how a cuttlefish’s eye worked, your mind would be blown.

The varifocal is the crown jewel of optometry. Form and function meet, and disappear. Miraculous engineering, which we look down on because Doris is rocking it.

A single lens containing multiple focal points reminds us there is more than one way of looking at things. Seeing the bigger picture requires a shift of vision. Peripheral sight, meanwhile, alerts us to the fuzzier ways which life, and love, sideswipe us.

Maybe this is how a cuttlefish’s eye works. Maybe there was an episode of Blue Planet all about it. I didn’t see it.

Photograph by Shaw & Shaw