The Reason Pirates Wore Eye Patches Isn't What You Think

While piracy has been around since antiquity, the popular modern-day notion of pirates didn't really come into being until the 17th century. It is around this time that an explosion of piracy occurred in Asia, the Mediterranean, and the Caribbean. According to History, pirates like the Barbarossa Brothers, Blackbeard, Captain Kidd, and the most prolific female pirate of all time, Ching Shih, all thrived during this era.

Of course, one of the most notable things that comes to mind when discussing pirates at any great length is the eye patch. In just about any type of media about pirates, at least one individual pirate will certainly be sporting an eye patch. It has been widely assumed that pirates wore eye patches for the most obvious reason: damage or removal of the eyeball. Yet, historians are now beginning to think that there was also a strategic use for the eye patch.

While there is no historical proof for the theory, it's believed by historians that some pirates wore eye patches to help see in the dark. While working on ships for months at a time, men would have to work between the upper decks of a ship that would only get light from the outside. Since this is the 17th century, there was no electricity. Meaning that the lower and innermost decks of ships had little to no light in them. Essentially, anyone working in the lower decks was virtually blind.

According to Scientific America, it can take up to 30 minutes for the human eye to adjust to darkness, in a process known as "dark adaptation." This, of course, puts the pirate visiting the lower decks at a disadvantage. However, if the pirate heading into the bowels of the ship sports an eye patch over one of his eyes, it'll cause the eye to stay in permanent darkness. Therefore, he/she will be able to see when going from the broad daylight of a midday sky on the main deck to the eternal darkness of the inner decks of pirate ships.

To test the validity of the eye patch theory, the show "Mythbusters" ran a pirate-themed episode back in 2007. In the episode, they tested the theory, deeming it was "plausible" that a pirate might actually wear an eye patch to help maintain dark adaptation in one of the eyes.

Interestingly enough, the FAA also suggests that pilots take advantage of dark adaptation while flying. The Aeronautical Information Publication (AIP) states that any kind of dark adaptation a pilot may have is lost within seconds of being exposed to bright light. Therefore, "the pilot should close one eye when using a light to preserve some degree of night vision." So, while there is no real historical evidence that pirates used eye patches to this degree, as "Mythbusters" concluded, it's definitely possible that an enterprising pirate figured out that eye patches are definitely more useful than hiding a bad eye.