Lethargy and facial swelling

My cat has conjunctivitis and I treat him with eye drops regularly. I administered his eye drops as usual last night and noticed today that he's lethargic and his face is swollen between his eyes. He's still eating, drinking, using the wash room and responding to affection.

Could it be an allergic reaction? Maybe I accidentally poked him in the eye while trying to get the drops in?

I'm not really sure what this might be, but since he's lethargic, I would suggest a call/visit to the vet.

I agree that a trip to the vet is in order.  It could be a reaction to the meds or it could be a blocked tear duct.  Whatever it is, the kitty needs vet attention.  Let us know how it goes.