I shouldn't have been so fixated on eyes in my previous post...Poor Tonka. I don't know what he did. I don't see any signs that his actual eye is hurt, so that's good.
**Evening update - his eye is much better tonight. I had rinsed it with saline and I put some antibiotic eyedrops in it tonight for good measure. I think it'll be fine soon. Either there was something in there and it flushed out, or more likely he bumped it or got stung by something.**