The picture of a stereotypical pirate is usually someone wearing a long coat, a three-pointed hat, and an eye patch. While the first two are easily explained as appropriate garb for the period in which pirates ruled the seas, the eye patch is an anomaly that seems more like a modern add-on to give the customary costume a unique touch.
However, the truth is that the eye patch was part of traditional pirate outfits. While it’s unlikely that enough pirates lost an eye to warrant it becoming synonymous with piracy, there is another plausible reason that may explain why the eye patch was an essential part of their look.
Patches Helped Pirates Adjust Their Vision for the Dark
Living with a bounty on their heads and enemies at every turn, pirates had to be ready at all hours of the day for whatever crossed their paths. Come nightfall, adjusting to the shift from light to dark was essential. On starless and moonless nights, the sea could be pitch-black. Historians believe that pirates used eye patches so they would always have one eye well-adjusted to the dark. That means that when the pirates would encounter a dark area, they could move the patch from one eye to the other and hence always have one eye perfectly adjusted for the dark.
According to Scientific American, it can take the human eye up to 30 minutes to adjust to the darkness. For pirates, those 30 minutes could be the difference between ending up on the ocean floor and getting a jump on incoming opposing flags.
But Is This Theory Plausible?
There may be no pirate artifacts or historical records that support this theory, but there are real-world applications to help prove this hypothesis.
The team behind the TV show MythBusters put this idea to the test in a 2007 pirate special. Mimicking the pitch-black environment that pirates would often encounter, the team set up a dark room and sent in light-adjusted eyes. In the dark maze, they stumbled and had a difficult time making it to the exit.
A second dark room served as a maze for eyes that were covered for 30 minutes. This room was completed in significantly less time, which supports the theory that pirates wore patches in preparation for the nighttime.
Pilots Train Their Eyes in a Similar Way
To further support the notion that eye patches were used to make navigating the night easier, the FAA Flying Handbook suggests that pilots should also train their eyes for night flights when off the clock. “By closing or covering one eye when exposed to light, some night vision acuity is retained in the closed eye,” the handbook reads.
While there is a relatively long gap between the age of piracy and today, the concept remains the same. With one eye always in the dark, there is a greater chance of being able to see regardless of how dark it might be.
Forever a Historical Mystery
Despite the plausibility of this theory, it’s not enough to assume that adjusting to the dark is the primary reason why pirates covered one eye. While the reasoning may make sense, until some historical document or journal clearly states the purpose of eye patches, the answer will forever be an assumption.