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.
