Thanks to all the folks who replied to my post. I thought it might be useful to summarize all the responses in a single place, so here we go:
Brian:
Prefers larger lenses to avoid tearing while riding fast.
Opted against progressive bifocals because of the loss of field of view.
Opted for polarized lenses.
William:
Opted for photochromatic non-polarized progressive lenses.
In retrospect he would get polarized lenses.
Bought them at UC Berkeley School of Optometry.
Jim:
Kimber:
Opted for a pair of distance-only sport sunglasses with polarizing lenses, going from clear to a dark grey.
Richard:
Started with Rudy Project's RB3 then switched to Rydon with distance-only grey photochromatic lenses.
Brian:
Got new lenses for an old pair of Oakley frames.
Julia:
Got Rudy Project sunglasses with progressive lenses that change from clear to tinted.
Bought them at Crank Too.
Eric:
Got the Rudy Project Rydon's because the shape is compatible with lenses that correct astigmatism.
Opted for red photochromatic lenses.