2026 is also a year of anniversaries for Citizen. After the Japanese giant celebrated 55 years of Super Titanium in 2025 and the brand’s centenary in 2024, this year Eco-Drive technology marks its 50th anniversary. Following celebrations in Paris in 2024 and 2025, the focus shifted to Italy, with a major international event at the Bisazza Foundation in Montecchio Maggiore, in the province of Vicenza.
The event provided an opportunity to retrace the history of Eco-Drive, from the 1974 prototype – which was not yet sufficiently developed for commercial production – to the 1976 Crystron Solar Cell. The latter is considered the first light-powered analogue wristwatch, thanks to eight monocrystalline silicon cells arranged around the centre of the dial. Ten minutes of direct sunlight ensured 24 hours of operation, with a claimed accuracy of 15 seconds per month. The technology did not yet bear the Eco-Drive name (introduced by Citizen in 1994), but overall, the foundations had been laid.
THE NEW ECO-DRIVE PHOTON
Fifty years on, that technology – refined, improved and incorporated into dozens of models – is at the heart of a new project: the Citizen Eco-Drive Photon, a commemorative edition that reinterprets the brand’s photovoltaic technology through a contemporary design centred on light and its visual effects.
The name ‘Photon’ refers to the photon, the quantum of energy associated with light. The name is in keeping with the model’s identity, in which the operating principle of Eco-Drive is interpreted through a complex and recognisable aesthetic design.
This is not merely a commemorative model. Photon was conceived with the aim of translating the principle behind Eco-Drive into an aesthetic language. The designers have achieved this by transforming the dial into a meeting point between technological research and experimentation with materials. The result is a watch that stands out for the dial’s multi-layered construction, its reflective surfaces, a Super Titanium case with faceted geometries, and an seamlessly integrated bracelet.
THE PHOTON’S THREE-DIMENSIONAL DIAL IS INSPIRED BY THE PHYSICS OF LIGHT
The most distinctive feature of the new Citizen Eco-Drive Photon is the dial, conceived as a multi-layered structure in which light does not merely serve a technical function, but becomes an integral part of the watch’s aesthetics. Its design is inspired by the physics experiment known as the ‘double-slit experiment’, which demonstrates that light and matter can behave both as particles and as waves. Without going into too much detail, in the experiment, when light waves pass through two slits, they overlap and interfere with one another – with the crests reinforcing each other and the troughs cancelling each other out – producing a pattern consisting of alternating light and dark bands.
Inspired by this phenomenon, the dial features two thin overlapping metal elements, featuring openings that evoke the propagation of waves. They represent the passage of light through the dial itself and reveal glimpses of an underlying surface that generates reflections and colour variations depending on the viewing angle. The dial cover also features slits, creating a multi-layered structure that lends visual depth.
The dial’s distinctive vibrancy comes from the use of what is known as ‘structural colour’: the shades are not achieved solely through traditional pigments, but result from the interaction of light with microscopic surface structures. This creates a shifting visual effect, which lends depth to the dial and makes the watch appear different depending on the lighting conditions.
THE E036 CALIBRE: ONE YEAR OF AUTONOMY ON A FULL CHARGE
From a technical perspective, the key development is the new Eco-Drive calibre E036, a quartz movement powered by natural or artificial light. This solution eliminates the need for periodic replacement of a conventional battery and represents the very heart of Citizen’s technological identity.
The most significant figure is the claimed autonomy: up to 365 days on a full charge. This result significantly reduces the watch’s reliance on light exposure during daily use, although keeping the watch adequately charged remains important. For an anniversary celebrating a technology that converts light into energy, autonomy plays a central role in the product’s narrative.
The movement has a stated accuracy of ±15 seconds per month. The one-year autonomy is therefore one of the most interesting aspects of the new generation of Eco-Drive, combining the practicality of the technology with greater flexibility in how the watch is worn and stored.
CITIZEN’S SUPER TITANIUM EMBRACES CONTEMPORARY GEOMETRY
The case and bracelet are made from Super Titanium, a material developed by Citizen to combine lightness, scratch resistance and comfort on the wrist. The surfaces are treated with the proprietary Duratect technology, available in different finishes depending on the version. The proportions are relatively compact for a watch with such a complex design: the case diameter is 39.6 mm, whilst the thickness is 9.9 mm. The subtly octagonal cushion shape creates visual continuity between the case and the bracelet, preventing the more pronounced geometric lines from appearing excessively rigid.
The double-curved sapphire crystal, featuring an anti-reflective coating, completes the construction and enhances the dial’s legibility. Water resistance is rated up to 5 bar, a level suitable for everyday use. This combination of details demonstrates how Citizen has sought a balance between a strong aesthetic identity and functional features designed for regular wear.
CITIZEN ECO-DRIVE PHOTON: TWO VERSIONS, TWO INTERPRETATIONS OF THE DESIGN
The Citizen Eco-Drive Photon is available in two versions, each limited to 5,000 pieces worldwide. One, with a silver-coloured case and bracelet (€ 890), has a luminous appearance, in which the metallic surfaces highlight the textured dial. The yellow seconds hand adds a bold splash of colour. The black and gold variant (€ 990) has a more assertive character, with the contrast between the dark finishes, the gold-coloured elements and the purple seconds hand making the watch visually more striking.
The two models share the same dial design, calibre and key technical specifications. What sets them apart are, above all, the finishes and the way these interact with light. The caseback of each features the Eco-Drive 50th-anniversary logo and the individual edition number of the watch. The dedicated packaging also echoes the slotted motif of the dial, extending the design theme beyond the watch itself.
CONCLUSIONS
With the Eco-Drive Photon, Citizen has therefore chosen to celebrate half a century of research without merely revisiting elements from its archives. Rather, the project aims to interpret the technology that has helped define the brand’s identity, transforming its fundamental principle into a visible design element. The three-dimensional dial is the most effective embodiment of this philosophy: the light that powers the movement is also what generates the colour variations and the depth of the surfaces. Rounding off the design are Super Titanium, the balanced proportions and a stated autonomy of one year.
The Photon therefore appeals to those seeking a technologically advanced quartz watch, but also at those who value research into materials and aesthetic design. More than a simple tribute to the past, it is a statement of intent: for Citizen, the history of Eco-Drive remains fertile ground on which to continue shaping its own future and that of watchmaking.
By Davide Passoni