Ohh, I’ve been hit in the eye with projectile semen and it stung a LOT. My eye was red and puffy for a few days. I’ve since learned to turn my head and close my eyes, btw. Don’t want that happening again.
The normal pH of semen and tears is the same range - 7.2-8.0. But that’s a pretty big range, so if you’re on the lower end of that and your partner the higher (assuming the semen in your eye isn’t yours), then yes, that could cause irritation.
The most worrisome part of getting semen in the eyes is that it’s a great way to spread STI’s, and herpes in the eye royally sucks.
Surprisingly, semen’s not particularly saline, I was taught, but I can’t seem to find numbers on that right at the moment.
When something hits your eye at high velocity it hurts, then it stings. I don’t have any experience with semen, but I did get mud in my eye once. It stung for the rest of the day and my eye was red the whole time.