Ray-Ban Aviator Sizing Guide

Ray-Ban Aviator Sizing Guide:

Tried on a few pairs in-store and love the look and feel of the Ray-Ban Aviators. However, when it came time to order, I was stumped with the sizing. One time the clerk told me that the sizing is most likely "medium."

Online however, measurements are listed as:
55mm
58mm
62mm

Exactly which of these measurements correspond to small, medium, large?

Would love some help and could possibly make this into a guide of some sort as google results in no finds of "Ray-Ban Aviator sizing" etc.

TIA


P.S.
For the record, if this has been asked/posted please forgive me for not using the search button.

If you are looking for a medium fit Ray Ban aviator sunglasses, I would go with the 58 mm lens size. 55mm corresponds to a smaller size and 62mm is a larger size.

Thanks, another question is whether the following is an authentic seller?

http://www.shadesdady.com/Ray-Ban-Aviat ... ash-58.htm

I'm not sure about this site. I know that OpticsPlanet sells only authentic eyewear. Your purchase will be backed up by our 100% satisfaction guarantee and full manufacturer's warranty.

http://www.opticsplanet.net/ray-ban-sunglasses.html