Long time ago I received my allergy test results: moderate to dust mites and mild to dog/cat fur. I never had a problem with the latter.

Yesterday I patted a mate's cat who shed a lot of fur. Then I must have rubbed my eye afterwards or something - my left eye swelled, reddened and became itchy. It still feels a little swollen now after a sleep. I've proven my allergy result with hard, practical science.

Send help and antihistamines.