leland has no physical eye damage, and the vet suspected that his conjunctivitis was just an infection he probably picked up last week when he snuck out of the house for a few hours. i have some antibiotic ointment, which sounds very awkward to apply (it's an ointment & we have to wipe it into his eyelid) but should clear his infection right up. so that's the good news.
the bad news is that apparently leland has a level 3 heart murmur.
so i set up another appointment for next week, to get an x-ray, an ultrasound, & a multipurpose blood test (which will also check his FeLV status). they gave me an estimate of $479. there's no way to know whether the murmur is serious until the tests have been run (though he's definitely not lethargic, which is a good sign).
like i said in my previous post, he seems pretty healthy aside from the squinting, so i'm not too concerned just yet. but he could end up on heart medication for the rest of his life, & it potentially could be (or get) pretty bad.