I have a patient that who wears Nikon go on the last pair. This time she wants smaller frame since her high prescription. The last pair she has, B measurement is 27, the B measurement on this new pair is 25. I found that the minimal fitting height for Nikon go is 18 mm. The seg height on new pair is 17mm, the distance portion is around 8mm. I still tried order Nikon Go, it went through. I'm just worried if this patient gonna be ok with new glasses.