What should I do if I meet an acquaintance and get misunderstood when I go out without glasses?

If you have any contact with this acquaintance at ordinary times, you can choose to say directly: I didn't bring my eyes (or contact lenses) that day, and I didn't see it clearly at that time. In retrospect, I thought it should be you. Sorry for the detour: when chatting with him from time to time: I met XXX yesterday. I didn't have eyes at that time. I couldn't see clearly at all. He didn't react until he said hello to me.