Thickness of lenses
It is not only your prescription that will determine the thickness of your lenses, your Pupillary Distance and the frame itself also plays a part.
Full rimmed frames do a good job of hiding some of the lens thickness. If you have a higher prescription we would advise you to try and steer away from semi-rimless and rimless frames as they will show the full thickness of the lens.
Any increase in the size of frame from your current style will likely show in an increase in the lens thickness.
An increase in your prescription will mean an increase in lens thickness. The more short-sighted you are it is the edge thickness that will increase and the more long sighted you are it is the centre thickness that will increase. You can counter-act this by using a high index lens.
PD - Pupillary Distance
If you have a small PD and are wanting to choose a large frame, this will increase the thickness of your lenses. It is best to choose a frame where the width of one lens, including the bridge width, is equal to your PD to get perfect solution.