The Truth About Pirate Eyepatches
When people think of eyepatches, it is highly likely that they're also thinking of pirates, too. Pop culture and films have inundated the average consumer with countless depictions of pirates who sport them. So it's only natural that people associate the specific piece of eyewear with piracy. But the assumption pirates wear eyepatches didn't just spring out of thin air. Pirates actually did wear them, and not for reasons most people would think.
In modern times, eyepatches are worn over an eye that is healing from an injury, or one that is disabled, sensitive, or simply hiding what's not there, per Northwest Eye Design. In the case of pirates, most of them did not have any of the reasons above for wearing one. And while some were an eye short, more often than not, pirates actually had perfectly fine vision in both eyeballs. So why did they resort to becoming wearers of the eyepatch?
The answer might be strictly scientific. Pirates would wear eyepatches as an assistive tool to adjust to varying levels of light their eyes were exposed to. Have you ever woken up from sleep and strained your eyes to the sunlight beaming into your room? That's the same concept for the inverse, coming from a brightly lit space and right into a dark one.
Pirates wore eyepatches to adapt their vision
According to Scientific American, it takes the human eye 20-30 minutes to adapt to an optimal function just to navigate in darkness immediately from light. Different parts of the eyes have their own role to play in overall vision, and in order to catch up to a sudden change of brightness or darkness, it can take some time. The concept is called dark adaption. But if you're already prepared, then it shortens the adjustment time, which is what pirates were apparently doing.
As Ancient Origins tells us, because pirates were constantly on guard for an attack, they prepared themselves to fight above and below the decks of ships — basically optimizing their fighting ability and not allowing it to be impaired by their eye having to take a half-hour to adjust to the light conditions. The bottom deck areas of these ships they overtook were always pitch dark. But with an eyepatch covering an eye already in darkness, a pirate could simply remove his patch and still be able to see out of that eye to defend himself.
While the idea that pirates wore eyepatches for expected combat is considered a theory, science supports it if it's true. It's also why ophthalmologists can recommend wearing sunglasses or some kind of sun shade before going to bed, to help with the eyes' light adjustment, says CooperVision.