Dizzy with new gles?

hi i just got a new prescription gles and the problem is that when ever i sit or am standing still with the gles im fine but whenver i walk i get dizzy with my new gles(3days old) and tend to switch back to my 5month old gles. is this normal? how long should i feel dizzy and headaches. when i watch tv with them its fine but when i go out i get dizzy. also things seem to kinda blur out everytime i blink with the gles on. plz help me footprint, or any other optician online. id like to know if i have to bring them back. i have to squint to see like 40 or 50 ft out and see fine like 10 ft out from something with the glasses.