I went through 7 years ago and my eyes were 2.5 and 2.75(so similar to yours) and yes I was told during the medical that nats do set 3 as a general guideline as the limit to take in to account eyes do tend deteriorate with age.(although individual cases are looked at) If your prescription has been steady then there should be no issues, however if you are keen to make this your profession then go for it sooner than later, to avoid any hassle
