January 31, 2014

What happened to superior glass lenses in eyeglasses? It's all plastic now

An ongoing theme here is how lame and crummy our everyday visual culture has become over the past 20 years. This has been reflected in technological changes, where the new mindset and tastes among consumers has allowed certain technologies to rise and others to fall by the wayside.

For example, the replacement of warm, lush film photographs with their dramatic range of shadow-through-light tones, by the harsh, washed-out digital images that blow out the bright spots.

It turns out that there's an even more basic visual technology that's recently been adulterated, and a cheap imitation being fobbed off on the public. Namely, the replacement of plastic instead of glass for prescription lenses.

I've been wearing contacts more or less since I first needed vision correction in 12th grade. But with money being tight, I decided to not buy another box and to just wear glasses for the second half of last year. I'd worn glasses a little bit before then, but had thrown them out once the prescription needed to be stronger.

My brother donated a pair that were very close to my own prescription. They have plastic lenses, which became the norm circa 2000, almost right after I got my original pair with glass lenses, just in the nick of time. I've gotten new contacts, and after nearly half a year of plastic-lens glasses, it really highlights how deficient they are. And I don't recall having these problems when I occasionally wore glass lenses before.

Although I can see things at a distance with the plastic lenses, wearing them reveals many faults compared to good old glass lenses or contacts. Glass has a greater visual acuity than plastic, in other words you see things more sharply and clearly, with minimal distortions -- y'know, the primary thing glasses are meant for.

With plastic lenses, things look flatter and duller, almost like there's a translucent fog. And there are more aberrations, many that I can't quite put my finger on. One is obvious, though -- plastic is more reflective, so you're more likely to see your own eyes, face, and head hovering in your field of view. If you want to improve that, then you have to pay for a separate anti-reflective coating to be sprayed onto the lenses -- y'know, instead of buying them ready to wear. Cha-ching.

Plastic is also way more high-maintenance. Dust, eyelashes, skin oil, you name it, gets stuck to plastic more easily than glass, and is harder to remove. Unless they're caked in grime, glass lenses can be wiped off with cotton. Plastic requires a specially formulated cleaning solution and a microfiber cloth, which aside from being Cha-ching is also more inconvenient to carry around in case you need to clean your glasses.

Plastic scratches way more easily. I'd only worn the plastic lens pair for half a year, and there are already visible little scratches on both lenses. I don't know how, since I didn't take a key to them or anything. But perhaps if they're in your coat pocket, a credit card, key, button, or a fingernail wandering in to dig them out could be enough to leave scratches. Glass almost never scratches, not in real-life conditions. Sure, you can add an anti-scratch coating to plastic lenses, but Cha-ching.

Plastic also doesn't withstand the elements as strongly as glass does. Granted, I haven't had them melt or anything yet, but the greater strain they'd face in hot weather, cumulatively over 10 or 20 years, means they're going to crap out earlier than a pair with glass lenses would. Ditto the frames, which is a separate matter. But glass lenses used to come in metal frames, while now it's plastic with plastic.

Glass does shatter easier, but a normal person will almost never experience this. Don't wear them when playing sports or taking mortar fire, and you'll be fine. Plastic needs to be replaced more frequently due to scratching than glass needs to due to shattering, plain and simple.

Glass is also denser and so tends to weigh more, although by the same token tends to be thinner and thus less unattractive. As a correction -- free, not an upgrade -- the temple arms of the frames used to angle farther down behind your ears to keep them from sliding. Now the angle is shallower and the length shorter behind the ear.

These two aspects of glass get so overblown in the optician industry's propaganda, just to try to sell you a poorer quality product that you have to replace more often and purchase several upgrades to make it even basically functional. Hypothetically, glass lenses will weigh more and shatter easier.

Yet, I did a little thing called a reality check and found out that none of that matters. In movies, TV shows, and pictures from the 1990s (before the rapid shift to all-plastic), do you see people with glasses that are constantly falling off their nose, or sliding so far down that everyone is tilting their head back just to see straight? Do yearbook pictures show half of the students with eye-patches due to glass lenses shattering in their face? Do you or anyone you know remember making frequent trips to replace your lenses because you kept throwing them against brick walls?

Conclusion: glass lenses are untouchable for visual acuity -- the very reason you bought the damn things -- and for being low-cost and low-maintenance. The supposed weaknesses of glass rarely or never became a problem in reality.

Here's another reality check: which other optical devices try to sell plastic lenses to their customers? None. They might try to sneak it in, but they'd never announce let alone brag about it. Glass lenses still rule for photography, cinematography, telescopes, binoculars, microscopes, and so on.

You'd have to be high on drugs to try selling camera customers on the superiority of a plastic lens. "Don't let that OLD-FASHIONED glass lens WEIGH YOU DOWN, or SHATTER IN YOUR FACE. Plastic lenses will set you free and save your life!"

As usual these days, the public doesn't give a damn about their everyday lives becoming lamer and crummier, as long as they can get a rush out of chasing phony progress. So, not only do the opticians get to sell us cheaper junk, they get an even more grateful response from customers -- "finally, progress in eyeglass design!" It's one thing if, like me, you didn't know the things were plastic at first and only developed a hunch over time that these glasses stink. But to see people celebrating plastic glasses as though it were a great leap forward, is depressing.

Which is why the optician can still be found in your local strip center doing good business, while most of the other specialized professionals have long fled -- hardware, furniture, cameras, photo labs, and so on. The eye industry has always been expert at rationalizing their scams, and the elimination of glass lenses is only a new chapter in their long history of fleecing the public.


  1. Back about 15 (maybe 20?) years ago, someone developed a plastic with a really high index of refraction. A friend of mine went from glasses that were nearly 1cm thick to plastics that were about 3mm thick. So for people with really bad eyes, a certain kind of plastic was actually a big improvement. I doubt the standard-prescription glasses sold in drugstore are using that special plastic, though.

    Plastic is probably cheaper, and with insurance paying for more and more glasses, the insurance companies probably pushed for more plastic.

  2. Interestingly enough, the same goes for digital screen technology. Aside from matte displays, the best is glass screens. No one advertises plastic.

  3. Good point. I've never bought an LCD screen TV. Flat screen CRT shows the best picture quality, except for plasma (cha-ching). I think there's a flat screen CRT computer monitor sitting around back home somewhere that would be worth dusting off and hooking up.

  4. Good points.

    At the same time though, some of the high index concoctions that companies like Zeiss do, in the range of 1.74, are quite impressive in terms of acuity. Combine that with Transitions just released gen VII photochromic coating, and you've got something.

    Or of course, just get rid of your myopia with a bit of rehab. ;-)

  5. I wonder if there is anywhere you can still get glass.

    What the heck is a flat screen CRT? I dont think thats physically possible.


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