I had a laugh at this article from Reuters:

If film stars in sunglasses in dark clubs at night seem ridiculous, it looked even more baffling when beach volleyball players at the Olympics took to the court wearing frames with no lenses.

“The lenses fog up because of the humidity, so you can’t wear the glasses without popping out the lenses,” U.S. men’s volleyballer Phil Dalhausser told reporters on Monday.

High humidity is a regular feature of the weather in Beijing at this time of year.

Several beach volleyball players wear glasses at night to reduce the glare of floodlights or protect their eyes from flying sand but the frames serve no other purpose than sponsorship.