
Be seeing things
See things / Have hallucinations / Imagine things / Mistake one thing for another / Not see straight / For one's eyes to play trick on someone

Avere le traveggole 
Avere le allucinazioni
See things / Have hallucinations / Imagine things / Mistake one thing for another / Not see straight / For one's eyes to play trick on someone

Avere le traveggole 
Avere le allucinazioni
Meanings
To have hallucinations
Examples
Am I seeing things or is that your husband, over there sitting at the restaurant table? Isn't he supposed to be abroad for a convention?
Ho le traveggole o quello al ristorante è proprio tuo marito? Non doveva essere all'estero per un convegno?
I can't believe it! I must be seeing things: my daughter cleaned up her room!
Non ci posso credere! Devo avere le allucinazioni: mia figlia ha pulito e riordinato la sua camera
Listen to me: your eyes are playing tricks on you! John cannot possibly be the guy you saw last night: John has been in the hospital, in intensive care, for a week
Ascoltami bene: hai le traveggole! Non può essere Giovanni quello che hai visto ieri sera: Giovanni è in ospedale in terapia intensiva da una settimana