In 2016, Omega filed a patent application for a dial with luminous indices. Not totally unusual, you say. However, these are illuminated via an electric light source (likely an LED) under the dial. The patent discloses a switch in the bezel that activates the illumination.
The patent has been granted in China, Japan, and in the European Patent office, but is still pending in the US.
Interestingly, the design kind of reads like a compromise in order to get the patent issued. The patent (as issued in the European Patent Office) requires that the illumination source be under the dial but above the movement, and then connected to a printed circuit board below the movement.
It also doesn't describe what the power source is, though it would be very cool if it could be powered by some capacitors and resistors, charged from movement of the watch, rather than relying on a battery within the movement.
In the end, I worry that the restrictions of having multiple printed circuit boards would make this watch too thick to be particularly viable - especially given that many Omega watches already run thicker than comparable watches without a co-axial escapement.