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You pay more initially, and have to look around more for it, but glass lenses hold up. Drop them. Stick them in your pocket with your car keys and pens. Clean them with whatever. Lose the case on day one. And they stay scratch free. For years.
Granted, this is only tenable if you have a “lighter” prescription.
I remove mine for close up stuff and thus my prescription has remained the same for over 20 years. I get new glasses not because the lenses scratch up, but because the frames break. I average new glasses every 8-10yrs.
Glass lenses.
I've never even been offered glass lenses. I thought they were phased out so that people would never get broken glass in their eyes.
I’m been smacked in the face and dropped them multiple times on concrete, industrial linoleum tile, and hardwoods. Never even seen a crack. I’m sure there are things that can do so, like an airbag exploding in your face, but I can’t imagine shattered broken milled plastic not being dangerous as well.
You have to ask for glass. They bury it in favor of the garbage that scratches up over time.
Quality plastic lenses can last that long. Often being able to keep glasses that long depends most on the stability of your prescription, and not going for bottom of the barrel coatings.
Glass lenses are harder to scratch, but are heavier for the same prescription and if you get hit in the face can shatter into shards that are quite damaging to the eyes.
If getting hit in the face is not a risk for you and you dont mind the extra weight go for it, but it's worth noting there are some downsides as well.
That’s why I said it depends on how light your prescription is. The husband has coke bottle lenses and cannot do glass. But he has to use the case. He has to use a special cloth to clean the lenses. He has to check against cleaning chemicals. He has to be very careful or they scratch, doesn’t matter what “special coating” is there. Those lenses do scratch up.
I’m less than -2 in both eyes so the weight doesn’t matter so much for me. I drop mine on the (bacterial lava) floor of a patient care area and I can grab whatever industrial, don’t use bare hands, wipe is available to purge the lenses of bacterial and viral load. And then stick them loose in a pocket with keys, pens, loose change, scissors, and they come out after a couple hours of that scratch free.
I get hit in the face. For decades. And decades of dropping them on concrete and everywhere else. No issues, breaks, or scratches thus far.
What are the stats on that? Are they a reality for the curved milled glass lens? Or is it a falsehood used to sell planned obsolescence lenses?
Lol. Bullshit to quality plastic lenses last that long. I mean sure, if you never drop them and baby the heck out of them.
The hardest clear plastic isn't remotely close to being as hard as glass or sapphire.
As for the shatter thing, often glass lenses will have a plastic layer on the eyes side of the lenses that prevents shards. This does mean that the inside of your glasses will scratch easier than the outside, but the outside is what always gets abuse.
Not all plastics are made equal. Two different 1.5 or 1.6 index plastics from different manufacturers will have different scratch resistance as well as different levels of aberration depending on how good their materials science is.
All plastic is softer than glass, yes, which is why any plastic lens you get has a hardcoat to reduce scratching and if it is from a quality lab, a scratch/antireflective coat as well.
If you've never had plastic lenses last very long, where you are sourcing them from is using inferior quality plastics with whichever lab partner they use. That or you a) leave them in a hot car and the heat damages them b) constantly leave them lens-face down on the table
But I have had people with very stable prescriptions keep plastic lenses in good condition for 15-20 years in extreme cases.
Laminated glass treatments may be used, but because they cause problems with the cutting machinery it is far more common in optical glass lenses to see chemical or heat treating. If these are done well, they can be quite resistant to shattering. This, however, really comes down to the individual skill of the person treating your lens and I've seen enough damaged eyes to be wary of them.
Another reason many labs have moved away from mineral lenses entirely is that they shatter when being cut to shape for your glasses, posing greater risk to the one doing the edging and significantly greater cost to the lab. Depending on the complexity of prescription they may shatter up to 3 or 4 times before one cuts properly into shape.
To add onto this, if you are using progressive glasses, you are certainly getting an inferior product as no lab I'm familiar with puts their new progressive designs into mineral. The majority only have designs from 15-20 years ago with terrible intermediate segments.