[snackbroken]

There is potential danger with a lens that can suddenly change to a second prescription. For example: imagine you're driving and your whole field of vision suddenly starts flickering in and out of focus. That would be incredibly distracting and pretty dangerous. Even if they just started focusing on 1 foot away it'd be quite bad.

[kelnos]

I don't think the FDA should be regulating based on whether or not it's safe to drive while using something.

There are plenty of FDA-approved drugs that should not be taken while operating a motor vehicle.

[therealpygon]

Are those drugs required for driving by the people who use them? I would expect if so, they would be tested more thoroughly before putting people on the road with a new drug, much like I’d rather not have someone driving toward me at a combined opposing speed of 100-120mph, two feet apart, while relying on “we didn’t think it will be a problem but we didn’t bother to test”.

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.

[jurgenburgen]

Or they could just ban using these glasses while driving. There’s plenty of people who don’t actually need to drive who would buy this.

[BigGreenJorts]

I think enforcement would be poor and therefore abuse would be high, but it could be granted that they're not safe for driving and therefore if you own a pair, you must switch to different (your old regular dual focus lenses) when driving.

[jurgenburgen]

Equally hard to enforce as people driving without their normal prescription glasses.

In both cases enforcement is reactive and happens after an accident has already happened.

[xp84]

> For example: imagine you're driving and your whole field of vision suddenly starts flickering in and out of focus

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.

[Nifty3929]

These glasses address farsightedness, which doesn't apply while driving. Worst case you just take them off.

[cperciva]

Plenty of us are simultaneously far and near sighted. I can't drive without glasses, but until I got progressive lenses I couldn't use my phone with my glasses on.

[WalterBright]

If you cannot drive without glasses, the sensible thing is to keep a backup pair in the car. After all, glasses can fall off and get lost under the seat, get stepped on, etc.

[ChrisC-POV]

Similarly, if a FAA-licensed pilot requires glasses to fly, it becomes a legal requirement that they carry a readily-accessible second pair while exercising the privileges of their license. This even applies if they use contacts (and, no, extra contacts don’t count :).

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).

[gchamonlive]

Still doesn't address the fact that if the glasses fail mid drive it poses a serious security risk if you can't pull over to switch glasses. Doing so in a highway in a moving car is inadvisable regardless of the technology behind the glasses.

[WalterBright]

Keep them within easy reach, like the driver door pocket.

[gchamonlive]

Changing glasses while driving on a high speed lane is dangerous regardless of where you put your spare glasses

[Noumenon72]

That's a smart idea, similar to how I keep a little cash in the car just in case. For example, I could get something in my eyes and have to remove my contacts, and an old pair of glasses would let me get home.

[t-3]

This is why I keep a pair of prescription sunglasses in my car. Added bonus is cutting the astigmatism glare while driving at night.

[elzbardico]

According to the article the technology can be incorporated into normal prescription lenses, and when the battery is empty, it would behave as that lens without any adaption for when focusing near stuff.

[1123581321]

If they are replacing bifocals, the wearer needs both a near- and far-sighted prescription. Far-sighted only would never need these.

Either failure mode would be dangerous while driving because you need to be able to read your dash.

[cout]

I don't need to be able to read my dash. I only need to see where the needle is pointing.

[WalterBright]

It's not a crisis if you cannot read your dash. How often do you look at the oil pressure gauge, for example? As for speed, just move with the traffic.

[bluGill]

I had a car with a broken dash. The only thing I missed for the month until I fixed it was the fuel gauge. I probably didn't estimate my speed very accurately but I was close enough to not get a ticket.

[WalterBright]

Yes, with my old cars I've had broken dashes, too. I discovered I maintained speed by the engine pitch - because when I drove a silent car, I couldn't seem to maintain a consistent speed!

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.

[bluGill]

I my case I tore the dash apart because the speedometer wasn't working, and the odometer is connected to that. Only after tearing the dash apart could I see the cable to the transmission wasn't turning. Until I found the real problem there wasn't a hurry as I removed the cable several times before I found what was really broke.

[1123581321]

Yes, it is a problem. There should be no controversy about saying that clear vision reduces distractions and confusion when operating something.

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.

[m463]

I think the car is 100% a use case. There are plenty of driving bifocals - they address the need to see the road, but also see the dashboard and controls.

Also, lots of older people get cataract surgery and can be perpetually farsighted (distance iol chosen)

[onemoresoop]

Add warning not to drive with them. Problem solved.

[DoctorOetker]

If it worked 99% of the time, compliance would be nil, but you don't want these drivers to be affected 1% of their commute

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.

[WalterBright]

The FDA needs to make the glasses as expensive as possible.