Did You Know
Did You Know: TDK Hid a 150-Nanometer Mirror Inside a Glasses Lens That Draws Images Straight Onto Your Retina
The flat meta-optic mirror lets about 80% of light through, keeps the picture sharp whatever your eyesight, and hides it from the people facing you. TDK's prototype is on show at CEATEC through Friday.
CHIBA, Japan · Maya Chen, Did You Know · Oct 16 2026
CHIBA, Japan - Did you know the most intriguing smart glasses display at CEATEC this week is a mirror you can barely see? TDK has embedded a flat “meta-optic mirror” just 150 nanometers thick inside an ordinary-looking eyeglass lens, and it bounces laser light straight onto the wearer’s retina. TDK calls it the world’s first direct retinal projection display for smart glasses built around a meta-optic mirror, and the prototype is on show at Makuhari Messe through Oct. 16.
Image: TDK
The trick is in how the mirror is built. Earlier retinal projection glasses needed a thick curved mirror mounted in front of the eye to steer the laser into the pupil, which is a big reason they looked like lab equipment. TDK replaces that curve with nanoscale reflectors laid out on a flat surface, some as small as one ten-thousandth of a millimeter. Their arrangement changes the reflection angle depending on where light lands, including what TDK calls a negative reflection angle that an ordinary mirror cannot produce, so a flat film does the job of a curved one. EE Times Japan, reporting from TDK’s Oct. 2 media briefing, describes a three-layer stack: a back layer, a dielectric layer, and a layer of trapezoid-shaped structures whose length varies across the mirror.
Screenshot: @ubergizmo on X
Because the picture is drawn on the retina rather than on a screen in front of it, TDK says it stays sharp regardless of the wearer’s eyesight, and the real scene and the projected image are both in focus at once. The mirror passes about 80% of visible light, which TDK puts on par with an ordinary eyeglass lens. It also avoids the rainbow-like eye glow that waveguide displays can show, and people facing the wearer cannot see what is being projected. According to EE Times Japan, the light needed for the projection is on the order of one microwatt.
Image: TDK
The mirror is made with deep ultraviolet lithography, the same family of semiconductor processes used to make chips, which TDK argues opens a path to cheaper mass production than complex waveguides. It currently sits on a sapphire substrate; EE Times Japan says a switch to silicon dioxide glass could lift transmittance by a few percentage points. The prototype shows monochrome images only. TDK told EE Times Japan it expects to begin product preparation for monochrome glasses between late 2026 and 2027, with full-color demo glasses due around March 2027. TDK’s own release targets full color and mass production “within the next few years,” helped by a business cooperation agreement with retinal projection specialist QD Laser.
Image: TDK
The project began in July 2022, according to Tomohito Mizuno of TDK’s Advanced Products Development Center, who said the team started “with no precedent to follow.” Prototypes were built at TDK Group companies SAE in Hong Kong and Headway in the United States. On Oct. 6, show organizer JEITA named the mirror winner of the CEATEC AWARD 2026 Minister of Economy, Trade and Industry Award. Ubergizmo’s Eliane Fiolet, who has tracked TDK’s prototypes since CEATEC 2024, tried the glasses on the show floor and noted that the mirror sits near the center of the lens. TDK plans to show the prototype again at electronica, Nov. 10 to 13. For an industry that keeps promising glasses that simply look like glasses, the surprise is how little of this display there is to see.
