h a l f b a k e r y
Professional croissant on closed course. Do not attempt.
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These glasses have flat lenses. The rear half of each is a Fresnel lens consisting of a thin layer of silicone oil behind transparent piezoelectric crystals linked to an array of indium tin oxide electrodes, and a thin protective flat layer at the front filled with another clear substance with a melting
point somewhat above body temperature, probably a heavier siloxane. Passing a current through the crystals changes their shape and the refractivity of the whole lens changes. Different patterns of current are possible in different parts of the lens, allowing for astigmatism. The lenses are adjusted by turning on heating elements to melt the substance at the front, then twiddles with the controls until the lenses are comfortably focussed. While holding that pattern, the lenses are then cooled back to body temperature, allowing them to freeze in position. This is done whenever the user experiences a change in their eyesight. They are sold with a Snellen chart, an ophthalmoscope with a fibre-optic attachment allowing one to do fundoscopy on one eye while looking through the other and assess the likes of papilloedema, diabetic eye changes and blood vessel changes, a booklet introducing one to optometry and a disclaimer concerning the need to consult a professional optician. The ophthalmoscope also has a USB attachment to upload images of the retina to a crowdsourced ophthalmology website.
One flaw in this, of course, is whether piezoelectric crystals are ever transparent.
It also makes lenses flatter, thinner and lighter.
eyeglasses w/ silicone-filled lenses, adjustable +/-6 diopters [afinehowdoyoudo, Jan 17 2009]
||[+] for the whizzbang technology (and clear description thereof). But I'm curious. What's wrong with LASIK?
||Not everyone is eligible for Lasik. Especially those people
who's eyes are changing (degrading) relatively quickly, which
would be the ones this idea would help most (if feasible).
||Thanks for the link, [iron_horse], i'll check it out in a minute.
OK, done that. I've heard of them before. I thought he had a problem with leakage, and clearly there's a problem with the liquids not being compressible, so i'd revise this to say there are reservoirs in the earpieces. His design doesn't look like it can deal with astigmatism.[SpaceCoyote], i understand there's a risk of opacity with laser eye surgery, and i'm uncomfortable with the consequences. I expect to be slated for this, but i believe there's a link between eyesight and body habit. This is most certainly not to the extent that i can sort out my twenty/two hundred visual acuity with it, but there is some improvement, and the motivation for doing something about poor posture would be taken away by eye surgery. Leaving that aside though, i would prefer to use glasses than either contacts or have eye surgery, because like many others i'm squeamish about that.