Citizen’s new limited-edition watches use a physics experiment to create a unique dial

Citizen has launched its limited-edition Eco-Drive Photon watches, now available for purchase in the US and UK. The two references, first announced in March with a planned autumn release, have arrived slightly ahead of schedule. The BJ6560-53W, featuring a silver-tone titanium case and a yellow seconds hand, is priced at $995 or £749. The BJ6569-59X, finished in black and gold with a purple seconds hand, costs $1,195 or £895. Both models are sold exclusively through Citizen's own online store.

The dial is the centerpiece of the design, directly inspired by the renowned double-slit experiment, which demonstrates that light behaves as both a wave and a particle. Instead of using painted colors or printed patterns, Citizen stacks two metal layers with precisely cut slits over a structural color film, which sits above the solar cell. Light passing through the slits produces shifting colors that change depending on the viewing angle — a visual effect that references the wave-particle duality of light. This approach also inverts the typical Eco-Drive formula: light-powered watches usually hide their solar cells behind semi-opaque dials, but here the slits make the light path visible, turning the energy source into a design feature.

The case is made from Super Titanium, measuring 39.6 mm in diameter and 9.9 mm thick, with a rounded octagonal shape and an integrated bracelet. Citizen uses its Duratect surface hardening technology: the silver version gets a titanium carbide coating, while the two-tone model features DLC with Duratect Amber yellow on the gold accents. The dial is protected by sapphire crystal with anti-reflective coating, and water resistance is rated at 5 bar.

Inside, the watches are powered by the new Eco-Drive caliber E036, designed specifically for this release. It is rated at ±15 seconds per month accuracy. The limited-edition status adds exclusivity, with both models marked as "exclusive" on Citizen's store. The combination of a physics-inspired dial, titanium construction, and solar-powered movement makes the Photon a distinctive addition to Citizen's lineup.