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Adjustable-Focus Glasses Can Replace Bifocals
Hugh Pickens writes "The NY Times reports that inventor Stephen Kurtin has developed glasses with a mechanically adjustable focus that he believes can free nearly two billion people around the world from bifocals, trifocals and progressive lenses. Kurtin has spent almost 20 years on his quest to create a better pair of spectacles for people who suffer from presbyopia — the condition that affects almost everyone over the age of 40 as they progressively lose the ability to focus on close objects. The glasses have a tiny adjustable slider on the bridge of the frame that makes it possible to focus alternately on the page of a book, a computer screen, or a mountain range in the distance. 'For more than 140 years, adjustable focus has been recognized as the Holy Grail for presbyopes,' says Kurtin. 'It's a blazingly difficult problem.' Each 'lens' is actually a set of two lenses, one flexible and one firm. The flexible lens (near the eye) has a transparent, distensible membrane attached to a clear rigid surface. The pocket between them holds a small quantity of crystal-clear fluid. As you move the slider on the bridge, it pushes the fluid and alters the shape of the flexible lens."
Don't use cleaning fluid, tissues, or even those special cloths. Use soap and water only. Run water over your lenses to get the larger dust particles off, then wet your fingers and apply a couple of drops of dish detergent to them. Use this to get any remaining dust and oily residue off the lenses by rubbing the lenses with your fingers. Rinse the lenses under running water. Repeat as required. You can shake most of the water droplets off, and if you want to get rid of all of them, dab the lenses with a soft cotton towel. You lenses should remain scratch free for years.
What's it like to get a shot in the eye? I assume they anesthetize you so that can't flinch or blink. But are you conscious?
They do apply a local anesthetic to the eye, but you are otherwise fully conscious and alert. They merely use a steel contraption to pin your head and shoulders down. ;)
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There's also soft toric lenses for astigmatism.
Yes, the lens stiffens with age. (There was a competing theory that it grows with age, and that focus problems arise because the focus mechanism doesn't have enough range of motion to adapt, but that apparently hasn't been borne out by further studies.
No, in general, lens replacement does NOT give you back focusing ability. There's one type of lens (Crystalens, referenced upthread) that restores accommodation for some recipients, but results vary widely, and regular replacement lenses don't accommodate at all.
What I *really* need is a new pair of eyeballs.
Not your eyeballs, just their lenses. They have soft contacts for astigmatism now, but if you have the money for it a CrystaLens is the way to go; I have one in my left eye and it's fantastic.
Its amazing how science has in some cases passed science fiction. In Star Trek IV there's a fictional drug called "retinox" that cures age related presbyopia by (presumably) softening the lens, and since Kirk is allergic to retinox, he has to wear reading glasses. One would think that McCoy could just transport Kirk's crystaline lens out and transport a CrystaLens into it, but the si-fi writers didn't forsee this new tech (it was FDA approved in 2003).
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You're correct; the "certain type of cataract surgery" is a new implant approved by the FDA in 2003. The older implants, the ones insurance covers, won't focus. But by the time you need cataract surgery your eyes won't focus anyway.
I have one of the new ones in my left eye. My surgeon said my outcome was better than average, but I'm better than 20/20 at all distances. I see better than most 20 year olds!
BTW, the new lenses move, on struts, making them devices. This means if you get these implants you're a cyborg.
Resistance is futile.
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