Seriously, how different was the prescription from your previous glasses?
If the prescription was a big change then it may take a while for your eyes and brain to adjust.
Keep checking that your distant vision is good; reading road signs and shop names is generally a good test.
The fitting of the glasses can be important especially if they are multifocal. Any good optician will gladly check the prescription and the fit for you if you're a customer.
The bigger the change in prescription the longer it takes to adjust. I always have trouble for the first couple of days especially judging depth. As has been said, give it a week to ten days and if you're not happy then go back to your optician.