On Saturday, after a 3-mile hike through the Presidio, I stood in a throng of tourists looking at the Golden Gate Bridge. As the crowd snapped photos of the landmark, I decided to join in.

But instead of reaching into my pocket for my iPhone, I tapped the side of my Ray-Ban sunglasses until I heard the click of a shutter. Later, I downloaded the photos that my sunglasses had just taken to my phone.

The process was instant, simple, unobtrusive — and it was powered by Facebook, which has teamed up with Ray-Ban. Their new line of eyewear, called Ray-Ban Stories and unveiled Thursday, can take photos, record video, answer phone calls and play music and podcasts.