There are plenty of FDA-approved drugs that should not be taken while operating a motor vehicle.
That said, there is certainly room for an improvement in funding so that the FDA could go through processes more efficiently, but “efficiency” is rarely ever achieved by cost cutting because it confuses cause with effect.
In both cases enforcement is reactive and happens after an accident has already happened.
Imagine you're driving with regular glasses and one tiny screw gives way and they fall off. Imagine you rub your eyes and your contact falls out. Those can't be 100% ruled out either.
But anyway, the FDA imposing a half decade of delays on this will do zero to prevent that from happening. The article says when unpowered they revert to being regular glasses for the main prescription. So the main reason they could glitch out like you suggest would be a software bug. After approval, a future software update could still introduce that bug anyway. So either the FDA has to find a way to review every software patch with perfect bug-detection abilities, or they are useless here and just wasting our money pretending to regulate things without adding any value.
Note that I'm not saying they have no role -- though I would say they do seem to be the worst in the first world at their actually needed job of balancing risk and access in the 'actual medications' department.
It is also a requirement for international flight operations under ICAO regulations. I’m pretty sure this regulation (or something close to it) is enforced by just about every flight-licensing authority worldwide.
It’s plain good sense and I’m glad it’s in there. A plane cannot pull over to the side of the highway while the pilot fumbles around trying to dig his glasses out from under the seat :)
(As a side note, this rule isn’t just for dropped spectacles: there have been cases where they literally get sucked out of the airplane if a cockpit window fails or where a bird strike causing facial injuries also damages the pilots glasses).
Either failure mode would be dangerous while driving because you need to be able to read your dash.
As for the gas gauge, the trick is to reset the local odometer at every fillup, and you'll have an indication of the remaining fuel. Some older cars don't even have a fuel gauge, they just have a lamp that glows when it gets low.
If you want to talk specifics, you’re supposed to be able to see your speed and how your car is performing. You should be prepared for contingencies, like your temperature changing or a yellow/red warning on the dash. You may need to deal with a problem in the car, like grabbing something that could slide under the pedals.
The same goes for farsighted driving. Yes, in most cases you could just follow traffic and you wouldn’t need to read street signs or look at traffic a mile ahead. But you need to be prepared for unexpected situations, and you’ll generally do worse just mentally managing your reduced vision.
I’ve driven without my glasses and tested an unexpectedly bad trial prescription in a car, if it matters.
Also, lots of older people get cataract surgery and can be perpetually farsighted (distance iol chosen)
Even if a person would be compliant, if they wore this most of the time, they wouldn't be accustomed to the varifocal lenses while driving, guaranteeing that whatever other solution than these autofocusing lenses they select for driving, they won't be adapted to them whenever they drive.