Open-Heart Automatic Watches: What Can You See Through the Dial?
Open-Heart Automatic Watches: What Can You See Through the Dial?
What is an open-heart automatic watch?
An open-heart automatic watch is a self-winding mechanical watch with an aperture in the dial that reveals part of the movement, often the balance wheel.
It gives you a view of a specific working component while leaving most of the movement covered. The dial remains in place around the opening, so the mechanism becomes part of the design without turning the whole watch into a movement display.
What can you see through the Heartmatique dial?
The Heartmatique product pages confirm these displays:
- Open-heart aperture: at 7 o’clock
- Small-seconds display: at 5 o’clock
- 24-hour marker: listed as a function
The Miyota 82S7 specification also lists an open-heart display, small seconds and a 24-hour display.
How does an open-heart movement work?
An automatic movement stores energy as the wearer’s wrist moves. A rotor winds the mainspring; the stored energy then travels through the gear train to drive the hands and other displays.
The balance wheel oscillates as part of the regulating system. The escapement sends impulses to the balance wheel, and its regular oscillation helps regulate the watch.
In an open-heart design, part of this process is visible through the dial. It gives the wearer a view of the mechanism operating inside the case.
The Miyota 82S7 inside the Heartmatique
The Heartmatique uses the Miyota 82S7 Japanese automatic calibre. Miyota lists these features and specifications for the movement:
| Specification | Miyota 82S7 |
|---|---|
| Winding | Automatic and hand winding |
| Display | Hours, minutes, small seconds and 24-hour display |
| Open-heart display | Yes |
| Frequency | 21,600 vibrations per hour |
| Jewels | 21 |
| Running time | Approximately 42 hours |
| Stop-second device | Yes |
See Miyota’s official 82S7 specifications.
Open-heart vs skeleton watches
Both styles reveal parts of a mechanical movement, but they do so differently.
| Feature | Open-heart watch | Skeleton watch |
|---|---|---|
| What is opened | A focused aperture reveals part of the movement | Material is removed from the movement’s plates and bridges to expose the wheels |
| Visual effect | Selective and framed | More of the mechanism is visible |
| Dial structure | Most of the dial remains in place | The movement becomes a larger part of the display |
The Fondation Haute Horlogerie’s explanation of skeleton watches describes removing material from plates and bridges to expose the wheels while retaining the structure needed for the movement to function.
An open-heart watch keeps more of the dial intact. It suits someone who wants to see part of the mechanism without making the movement the entire visual focus.
Open-heart vs tourbillon
“Open-heart” describes a view through the dial. A tourbillon is a mechanical construction in which a rotating cage carries the escapement, balance and hairspring.
The terms describe different things. A visible balance wheel alone does not make a watch a tourbillon.
The Fondation Haute Horlogerie’s explanation of the tourbillon describes the rotating cage and the components it carries.
Why is the balance wheel visible?
The balance wheel is a moving part of the watch’s regulating system. The Heartmatique product pages state that the balance wheel is visible through the dial.
That view lets the wearer observe part of the movement in operation. On the Heartmatique, the product pages place the open-heart aperture at 7 o’clock.
What should you look for in an open-heart watch?
The movement and aperture
Check which part of the movement is visible and read the calibre specifications. Winding, running time, frequency and other displays help explain what the watch offers beyond its appearance.
The dial and displays
Look at how the aperture works with the hands, markers and other displays. The opening should be easy to distinguish, and the dial should remain readable for everyday use.
Is an open-heart watch practical for everyday wear?
Yes. An open-heart watch can be worn every day with sensible care. Follow the manufacturer’s instructions when winding and setting it, avoid unnecessary impacts and strong magnetic fields, and clean and store it according to the care guidance.
The Heartmatique product pages list 50m / 164ft water resistance. Water-resistant does not mean waterproof; follow the manufacturer’s guidance for water exposure.
Frequently asked questions
What is an open-heart automatic watch?
It is a self-winding mechanical watch with an aperture in the dial that reveals part of the movement, often the balance wheel.
What can you see through the Heartmatique dial?
The product pages place the open-heart aperture at 7 o’clock and the small-seconds display at 5 o’clock. They also list a 24-hour marker.
Is an open-heart watch the same as a skeleton watch?
No. An open-heart watch reveals part of the movement through a focused aperture. A skeleton watch exposes more of the movement by removing material from its plates and bridges.
Is an open-heart watch a tourbillon?
No. An open-heart display shows part of the movement through the dial. A tourbillon uses a rotating cage that carries the escapement, balance and hairspring.
What movement does the Heartmatique use?
The Heartmatique uses the Miyota 82S7 Japanese automatic calibre.
Explore the Heartmatique
Final thoughts
An open-heart watch lets you see part of the movement while keeping the structure of a complete dial. On the Heartmatique, the open-heart aperture, small-seconds display and 24-hour marker sit alongside the Miyota 82S7 automatic movement.
The balance wheel’s motion gives the dial a visible connection to the mechanism inside.