Here's how fucked up it is imagine the only difference between having eyes and not having eyes is one tiny small area that if it breaks at any moment the immune system can "find" your eyes which is why eye damage needs to be treated right away. One tiny barrier keeps your eyes from being identified and if that breaks your worst nightmare.

It'll do the same to a man's balls, too

Our immune system is trained how to differentiate between what is supposed to be there and what isn't only on things floating around in the blood. Certain parts of the human body - like the liquids inside our eyes - are permanently isolated from the bloodstream, and so our immune system will never have encountered anything like it. That's why if it ever enters the bloodstream it can trigger an immune response.