Although Casio has been the alpha and omega of digital watches for decades, they have always had one tiny dark spot – literally. But 2025 is clearly the year when even a digital display can glow in the dark like it’s straight out of a superhero comic book. The new Casio Pro Trek series with a phosphorescent digital display.
Casio is with its new series Casio Pro Trek PRW-35LD-5JF and PRW-35TLD-7JF have done something that will leave many speechless – for the first time in history, they have equipped a digital LCD screen with a full phosphorescent coating that glows without the help of an internal LED backlight. In a world where we still debate whether smartwatches should look like mini phones, Casio elegantly demonstrates the middle ground of complexity with something that is quite simple… and ingenious.
The first digital watch that really glows
Sure, Super-LumiNova, Seiko's LumiBrite, and similar luminous coatings have been around for decades—but almost exclusively for analog hands. Digital display? Until now, it's depended on the push of a button. Nova Casio PRW-35LD-5JF series changes that. The LCD screen lights up on its own if it gets enough light during the day. The story goes like this: you expose the watch to a strong light source (say, a 200-lumen headlamp) for one minute and it will light up for the next hour.
For hikers, mountaineers, cavers and night adventurers, this is a pretty big deal. But who wants to scratch their watch with a cold finger at 2,000 meters to see what time it is?
A classic that hasn't forgotten about the future – Casio Pro Trek
Both models – the more affordable PRW-35LD-5JF and the more expensive PRW-35TLD-7JF – are based on the familiar and popular PRW-35 series design: 44.6 mm in diameter, 13 mm thick and weighing just 45 g (or 81 g for the titanium version). Compact, robust, and still comfortable to wear – Casio didn’t go the “bigger is better” route.
Inside, you'll find proven Triple Sensor technology (altitude, pressure, compass), Tough Solar power, and Multi-Band 6 radio time synchronization. Of course, there's also sunrise/sunset data, a thermometer, and cold resistance down to -10°C. Water? No problem up to 100 meters.
Premium or practicality – Casio Pro Trek?
The difference between the two models is mainly in the materials: the PRW-35LD-5JF has a bio-based resin strap, mineral glass and costs around $337. On the other hand, the PRW-35TLD-7JF bets on titanium elegance, sapphire glass with internal AR coating and titanium carbide coating, which puts it in the $600 league. But both watches are built for serious use in the field - just with various "cosmetic additions".
A bright future, but a few shady spots
Although this is a globally significant innovation for the Casio Pro Trek, Casio has not (yet) confirmed international distribution. Traditionally Casio Pro Trek The series remains partly reserved for the Asian market – which is sometimes frustrating for global enthusiasts. However, if the market cries out enough, perhaps this phosphorescent wonder box will also come to Europe or even the US.
Conclusion: really interesting watches
Casio Pro Trek PRW-35LD-5JF and PRW-35TLD-7JF are not just new watches – they are a silent (or luminous) revolution in the world of digital watches. In an era when most innovations involve multiple screens, sensors and apps, Casio shows that it is possible to be a pioneer with something as simple as a luminous coating. Minimalism? Maybe. Innovation? Absolutely. The need for a light button? Bye!
