framesdirect.com carries drivewear. Their prices are no great bargain,
but are lower than brick-and-mortar on name-brand lenses and frames.
eyeglasslensdirect.com sells lenses only, and also carries Drivewear.
You send in your own frame. They welcome either re-lensing or new
frames bought elsewhere. Lens prices are not low like Zenni, but
decent.
I've used both of these companies. In each case, I received good but
slow service, with excellent quality and workmanship on the lenses and
mounting. I have bought Transitions from framesdirect, but have not
tried Drivewear at all.
Ira is working on a review of this category of online providers, who
specialize in fancy frames and higher-end products like Drivewear. I
only use them when I can't find what I want or need at a cheaper
place.
I have a strong and unusual prescription, and usually have to pay
various upcharges at the bargain websites. If that's also the case in
your prescription, you may find that eyeglasslensdirect or
framesdirect ends up being not that much higher.
On the other hand, if you have a mild prescription and don't want
something specialized like Drivewear, it's hard to beat
39dollarglasses, eyebuydirect, or zenni, for basic glasses.