Ok, since I've posted this same answer three times in the past three weeks, I decided to try to get an official thread for this.
First things first. There is no 'best' mask that will work for every person the same. We all have different shaped heads and faces, and probably different shaped glasses. Since all pro level masks out today have similar thermal capabilities, the main difference is in style, color, and price. Since those are personal preferences, these threads usually go into "This Mask VS. This Mask" pretty quickly, and usually someone will recommend I wear contacts.
None of that here. Just facts and info.
Background: I wear a ProFlex now - I wore Profilers and a I3 in '07 and Flexs pre-'07 with my glasses - My glasses aren't huge like that Erkle kid, they have flexible frames with plastic lens so they don't break - I got them to wear while playing sports.
So, here's my secret formula:
Only two things really matter when it comes to wearing glasses under a paintball mask:
1 - Does the mask fit my face and over my glasses comfortably?
2 - Does the mask have the option to add a fan ('cause your glasses will eventually fog.)
3 - refer to #1 & #2
That's it! Find a mask that fits you. Don't ask me 'cause I don't know!
Play Hard! Play Safe!
-D
**NOTE**
If (when) you have problems with your glasses fogging up, try FogTech solution on them.
http://fogtech.com/fogtech.html