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Medical Forum / General / Vision / May 2005Presbyopia reversing on its own?
When I was young, I had very good eyesight. When I passed 40, I started to wear glasses to correct for farsightedness. As I grew older, the prescription got stronger. In the last two years (I'm 66), this process seems to be reversing. This has been confirmed by an optometrist, and now my old driving glasses are my reading glasses. I can drive day or night without glasses. The optometrist said that this effect may be a precursor of cataracts. Anyone know about this effect or where I can find more information on it? -- Tony Karp, TLC Systems Corp Techno-Impressionist Museum: http://www.techno-impressionist.com TLC Systems: http://www.tlc-systems.com > When I was young, I had very good eyesight. > [quoted text clipped - 11 lines] > > Anyone know about this effect or where I can find more information on it? Your optometrist is correct, it is called cataract myopic shift. Your presbyopia has not reduced however, it is your hyperopia that has reduced. As the lens in the eye ages it becomes more dense and changes refractive index and effective power. An increase in power means more myopia or less hyperopia, thus your driving glasses now work as readers. This is the same process that eventually results in cataract, cataract are a normal result of the aging process. For more detail: http://www.emedicine.com/oph/topic49.htm Dr Judy Probably is; the lens swells during the cataract development, shifting the refraction toward myopia or less hyperopia. Used to be called "second sight". Don't worry too much about it, but plan for a minor surgical fix within a year or two. I went through the process in Jan. and if I knew then what I know now, I'd have done it sooner. But be sure to go to a cataract specialist who does stitchless procedures under anesthetic drops only. w.stacy, o.d. > When I was young, I had very good eyesight. > [quoted text clipped - 13 lines] > Techno-Impressionist Museum: http://www.techno-impressionist.com > TLC Systems: http://www.tlc-systems.com > Anyone know about this effect or where I can find more information on it? Generally the process is called "nuclear sclerosis." The crystalline lens swells, its index of refraction changes, and it becomes less uniform. All of these contribute to the "myopic shift" that many people experience, usually after age 60 or so. -MT >> Anyone know about this effect or where I can find more information on it? > [quoted text clipped - 4 lines] > > -MT This certainly happened to me. The nonuniformity showed up by my seeing multiple images. I called it a fly's eye phenomenon because I had no better term to use for it. I still had remanents of this fly's eye image after implantation of a lens during cataract surgery. I still would like to have an explanation on why the multiple images were formed by the impland and why they went away with porperly fitted glasses. Bill > I still had remanents of this fly's eye image after implantation of a lens > during cataract surgery. I still would like to have an explanation on why > the multiple images were formed by the impland and why they went away with > porperly fitted glasses. I still think it's corneal irregularities forming multiple images, and a sphere-cylinder lens simply approximates them better, into a single image. It's hard to imagine any other explanation. -MT >> I still had remanents of this fly's eye image after implantation of a lens >> during cataract surgery. I still would like to have an explanation on why [quoted text clipped - 6 lines] > > -MT I am beginning to believe this explanation. Before my cataract surgery the images formed a scatter pattern such as might be produced by a shotgun. I just now took my glasses off in a darkened room and looked at an LED on my telephone from a distance of about 3 or 4 meters. I saw multiple images now strung out in an almost horizontal line. I was able to reduce the number images by stopping my pupil with a finger. Putting on my glasses merged the images. As a further check, I took my glasses off and looked a a rectangular window on my computer monitor through the glasses. The window remained rectangular when the glasses were in there normal orientation. As I rotated the glasses along the line of sight, the window began to look trapazoidal as the rotation angle deviated clockwise or counterclockwise. This is just what I would expect if my cylindrical axis were close to vertical or horizontal. Bill I > just now took my glasses off in a darkened room and looked at an LED on my > telephone from a distance of about 3 or 4 meters. I saw multiple images now > strung out in an almost horizontal line. I was able to reduce the number > images by stopping my pupil with a finger. Putting on my glasses merged the > images. When you say "merged the images" do you mean it eliminated all the extra images? If so, then it is without a doubt your astigmatism. If not, I mean if they are closer together, overlapping, whatever but still multiple, then it is multiple refractions, true polyopsia and is due to damage to the optics, either corneal, lenticular or both. > As a further check, I took my glasses off and looked a a rectangular window > on my computer monitor through the glasses. The window remained rectangular > when the glasses were in there normal orientation. As I rotated the glasses > along the line of sight, the window began to look trapazoidal as the > rotation angle deviated clockwise or counterclockwise. This is just what I > would expect if my cylindrical axis were close to vertical or horizontal. This is normal observation through cylindrical (astigmatic) lenses of any axis, not just 90 and 180. w.stacy, o.d. >> I >> just now took my glasses off in a darkened room and looked at an LED on my [quoted text clipped - 8 lines] > multiple, then it is multiple refractions, true polyopsia and is due to > damage to the optics, either corneal, lenticular or both. There were more than two images without my glasses. It was almost a smear of discrete and continuous images. My glasses merged all these images so that I could not distinguish the merged images from a single image. >> As a further check, I took my glasses off and looked a a rectangular window >> on my computer monitor through the glasses. The window remained rectangular [quoted text clipped - 5 lines] > This is normal observation through cylindrical (astigmatic) lenses of > any axis, not just 90 and 180. Without my glasses, the image on the monitor appeared to be rectangular. Putting on the glasses change the clarity of the window but not its shape. From that, I conclude that the cylinder was lined up vertially or crossed. That is, oriented at O or 90. Bill > Without my glasses, the image on the monitor appeared to be rectangular. > Putting on the glasses change the clarity of the window but not its shape. > From that, I conclude that the cylinder was lined up vertially or crossed. > That is, oriented at O? or 90?. Probably so, or close. Oblique cylinder causes a noticeable tilt, but it's proportional to the "cyl" number in your prescription. If the cyl is -075 or less, it might be hard to detect the distortion at 90 or 180, but it'll be there. It's even harder to detect once you "get used to it." Minus cylinder x 090 would make a square seem slightly smaller horizontally, and x180 would make it slightly shorter vertically. Of course the other meridian distorts too, unless your prescription is like pl-075 or +075-075. Any meridian with focusing power will have a proportional effect, enlarging if plus, minifying when minus. -MT > There were more than two images without my glasses. It was almost a smear of > discrete and continuous images. My glasses merged all these images so that I > could not distinguish the merged images from a single image. Does that mean the single image was clear, or was it blurred? If clear, it was just regular astigmatism. If blurred, and the blur is not correctible with spectacle lenses, it is irregular astigmatism or other kinds of aberrations that are not ever correctible with glasses. > Without my glasses, the image on the monitor appeared to be rectangular. > Putting on the glasses change the clarity of the window but not its shape. > From that, I conclude that the cylinder was lined up vertially or crossed. > That is, oriented at O€ or 90€. No, I'd conclude that the cylinder was lined up properly with your axis of astigmatism, whatever that might be. While it's true that oblique astigmatism corrections can distort shape slightly, especially when first introduced, it is minimal and unnoticed by most people, and oblique astigmatism is certainly not the same thing as irregular astigmatism. But then I think we're off on a tangent here... w.stacy, o.d. > This certainly happened to me. The nonuniformity showed up by my seeing > multiple images. I called it a fly's eye phenomenon because I had no better [quoted text clipped - 4 lines] > the multiple images were formed by the impland and why they went away with > porperly fitted glasses. Actually called polyopia or polyopsia, multiple images seen by one eye. I had very symmetrical triplopia (3 images) of things like head lights and streetlights when I was developing cataracts. They were kind of annoying but also kind of picturesque. Made a christmas tree 3 times more spectacular. I'm quite sure that mine were caused by disruption of the old lens nucleus along the embryonic suture lines because of the triangular symmetry of the images. Larger single disk lights looked like 3 petaled flowers and tiny lights at a great distance looked like little 3 bladed propellers. Mine were completely eliminated by the surgery, so could not have been corneal. Since yours persist (have you had surgery in BOTH eyes? If only one, you could be getting if from the unoperated eye), I have to assume you had some corneal damage. Hopefuly it will eventually heal. w.stacy, o.d. |
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