How does one count lens generations? is it by the date on the lens box (shown here are 10/22/2013 and 1/9/2014)? or is it counted according to the generation of the frame? I only ask because I've heard people say "oh those are 1st gen Ruby lenses" or "oh, those look like 2nd gen". All I know up to this point is that 1st gen Ruby lenses are more purple/red than yellow/reddish orange.