The field of view is 51 degrees. Snap puts that at a 24-inch monitor seen up close, or a 115-inch screen ten feet away, and it comes off a liquid-crystal-on-silicon panel, a chip that bounces light into the lens instead of sitting in front of it.
Meta's display glasses are 2D screens for notifications. Specs are made for spatial apps, closer to a Quest headset folded into a frame you can wear down the street, and the optical see-through housing is Swiss TR90 polymer.
The prescription inserts pop out.
Removable inserts cover a wide range of prescriptions, and Snap ships several nose pad sizes so the fit can be tuned to the face wearing them. That is a bigger deal on a pair with optics in the lens than on a pair with a camera and nothing else.
Outdoors is why the lenses are electric. Electrochromic lenses shift from clear to tinted in ten seconds, and the display quotes a seven-millisecond motion-to-photon latency, the gap between moving your head and the image catching up.
The lenses darken on command in ten seconds. Sunlight has no say in it.