waveguide display

A waveguide display is a technology that traps light inside a thin panel—like an eyeglass lens—and carries it to the wearer's eye, where it appears as text or images. Light enters at one edge of the lens, bounces along inside as if reflecting off mirrors, then exits right in front of the pupil, making characters seem to float in the field of view.

Think of the lens itself as an extremely thin light pathway. There's no small screen or projector hanging in front of the eye; instead, light carrying information travels straight through the transparent lens. This means the scenery beyond the lens stays almost fully visible, while text can still be overlaid on top of it.

The reason smart glasses use this method is that it lets information appear within the field of view without adding bulk. It's the technology behind glasses that can quietly display meeting summaries, translated subtitles, or speech notes right in front of your eyes—without needing a camera or a separate screen.

RayNeo's iO Glasses display text using only a green waveguide display embedded in the lens, with no camera or speaker. A transmittance of 97% and brightness of about 1,300 nits mean the technology shows text clearly while barely blocking the background behind it. Contrary to a common misconception, this isn't a tiny projector or camera device—it's an optical method that carries light through the lens itself to the wearer's eye.