Glossary
Heads-up display
A small display that projects information onto the lens so it appears in the wearer's view without them looking away.
A heads-up display, or HUD, places information in the wearer’s line of sight so it can be read without looking down or away. In glasses this normally means a tiny projector in the frame throwing an image onto the lens, where it appears to float in front of the wearer.
What it is used for
On AI glasses a heads-up display typically carries short, glanceable things: turn-by-turn directions, live captions or a translated line of speech, notifications, a viewfinder outline. It is not a screen for reading or watching, and the image is usually small, monochrome and confined to a narrow field of view.
A display adds cost, weight and battery drain, which is why most AI glasses leave it out and answer through audio instead. It is the clearest dividing line in the category: whether you want to see answers or only hear them.