Type 1 = Acute (example: anaphylaxis, hives).
Type 2 = Cytotoxic (example: OCP) .
Type 3 = Immune complex (example: scleritis, serum sickness).
Type 4 = Delayed (example: PPD, poison ivy).
One mnemonic that some people like is “ACID.” Personally, I just remember that the main Type 2 reaction we see in the eye is OCP.