It looks like a brilliant bit of technology in the advert: a watch which is powered by light and never needs to be fed a new battery.
Except for one thing.
My watch spends its daytime life up my sleeve, so when would one of the brilliant new ones ever see enough light to charge it up?
One of my watches is a 1970s Seiko self-winder, for which a gadget to rock it back and forward at night was (may still be) available for those people who don’t move about enough during the day to keep it wound up. Maybe the brilliant new light-powered watch needs to be put next to its own little night light when the owner is asleep to make sure that it has enough juice to keep going through the following day.
Maybe that’s a brilliant new business available to some entrepreneur: flogging such night lights.