One month ago I have gone off the pill, I have an appointment for a qualifying examination in 8 days. I simply didn’t think of it when I was making the appointment. Is it a serious contraindication? What are the possible side effects if I decide to undergo a surgery anyway?

Hormonal imbalance may extend the healing process. This is why it is not recommended to go off the pill in the perioperative period. One month is more than enough for the surgery to be safe. You should go back on the pill until the eyes are fully healed (1-3 months).