Sure but we have also lost things that you’d think someone would write down properly if only for the purpose of manifests or similar things. Like Roman concrete where all the recipes we had failed to note that you needed to use salt water specifically or how I believe it was British naval vessels had three standardized condiments which we know the first two I think it was mayo and ketchup but we don’t know what the third was we think it was probably vinegar due to its common use in recipes at the time but we aren’t certain. It’s often times the most mundane things that are lost, reminds me how in 40k it’s all but stated that the control runes for more ancient tech are probably just our symbols for power on/off or whatnot they just lost the cultural context.
It’s still a huge stretch to go from “this could possibly work, but there’s no evidence that it was ever used besides sailors often being drawn with eyepatches” to “ever single sailor on the ship wore an eyepatch, and everyone forgot why and also depicted most sailors as not having eyepatches for some reason”.
Oh I doubt they all used that but it could’ve been a backup/specialist method dependent on ship or crew member. It wouldve been enough that when combined with actual eye injuries which could’ve been caused by any number of things it got stuck in on a cultural level, it’s like how under shirts got labeled tank tops because enough tankers kept getting too hot in their tanks so they stripped down to their skivvies. Doesn’t take much for memetics to kick in on such things, which when combined with ill records can cause a weird dissident of information.
when combined with actual eye injuries
Doesn’t take much for memetics to kick in
That alone is enough to explain our observations (the trope).
So, to summarize your point, if this happened but not very often, it wouldn’t leave any evidence. We have no evidence, therefore it must have happened, just not very often.
Probably, there may be evidence if you cross referenced a bunch of old journals, possibly medical logs, and maybe familial oral traditions. But yeah without going through largely inane and scattered documents it’s probably one of those self perpetuating memetic things that pops up on occasion because for a short period of time an uptick in sailors with eye patches happened and it got stuck culturally.
The best you could probably do to actually disprove such a thing would be to find where the source was, which would in all likelihood come down to a certain model of ship or a specific cultural tradition. Hell given how commonly shit goes back to Odin it could be a lost form of worship that got wrapped up in with sailor folklore after the viking age.
