Pirates Probably Didn't Wear Eyepatches for the Reason You Think

Think of a pirate, and you probably think of parrots, wooden legs, and big black eyepatches. You might assume the eyepatch was just part of their "tough guy" look — to cover an eye missing or wounded in battle. But a more likely reason for pirates to wear an eyepatch has nothing to do with injury.

An Eye for An Eye

Pirates were constantly moving above and below deck, so they needed the ability to see in both light and dark situations. If you've ever walked from broad daylight into a dark room, you know how long it takes for your eyes to adjust to the darkness. That adjustment can take 20 to 30 minutes as your eyes slowly regenerate the photopigments they rely on to see in dim light. Wouldn't it be handy to have one eye already adapted to the dark when you need it? That's the idea behind a pirate's eyepatch.

Picture this: A pirate is fighting on deck in the sunlight, then suddenly has to switch to fighting below deck in nearly total darkness. If they had no eyepatch, they'd basically be blind down there — and then they could really lose an eye. But an eyepatch makes it so one eye is always dark-adapted. When a pirate goes below deck, all he has to do is switch his eyepatch to the other eye and boom, he can see in the dark. It's a superpower that we assume must have been worth the drop in depth perception!

Arrrgh You Serious?

In 2007, Mythbusters did an experiment to put this theory to the test. First, the team was sent from a well-lit space into a dark room to complete specific tasks without doing anything to their eyes. As you might expect, the darkness got in the way, and it took them about five minutes to finish. For the second part of the experiment, they kept one eye covered for 30 minutes, then entered a second dark room. The team was able to complete the tasks with ease in a fraction of the time. (Just to make sure it was the light and not the room, the Mythbusters went back into the second room with light-adjusted eyes and struggled just as much as they had in the first room.) In the end, the team ruled the theory "plausible." Keeping one eye dark-adjusted works, but there isn't much historical evidence for the myth in the first place. Let us know if you know any 17th-century pirates.

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If pirates are interesting to you, don't stop here. Keep learning more with "The Republic of Pirates: Being the True and Surprising Story of the Caribbean Pirates and the Man Who Brought Them Down" by Colin Woodard. The audiobook is free with an Audible trial. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Annie Hartman August 2, 2018

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