Last week Tara got a black eye from hitting it on something - don't know what though. I too noticed some bubbling at the inside corner of the injured eye. The swelling, size of a marble, went down by some 90% within 2 days and the bubbles were no more.
From what I've read the bubbling has to do with some sort of trauma - a blow, a foreign object, etc ..
Cliff. J. “May the best you’ve ever seen, Be the worst you’ll ever see,” From A Scots Toast by Allan Ramsay