I am trying to figure out if I can use a 1.67 high index lens vs.the 1.74 high index lens. The price difference is incredible.My prescription is -6.5 on one eye and -7.25 on the other with an astigmatism.It's twice as much to buy the 1.74 lenses and I am really wondering if that is necessary. I use plastic frames, oval style so a little thickness on the sides is no big deal to me. Any thoughts? What really is the difference between these two lenses?
>>> Which high index lens should I get? 1.67 vs 1.74?