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Medical Forum / General / Vision / March 2007eyescope
My dusty 1998 Edmund Scientifics catalog, there is an item called an eyescope. It says that you can "see the inside of your own eye". Apparently they no longer sell it :( I see a similiar item, no longer available: http://boreal.com/category.asp_Q_c_E_537867 Do you know where to purchase an eyescope (or the equivalent)? Can you see the retina? Can you see the optic nerve? bill The link you provided says if you use it: They can see strings of pearls, clusters of circles, radiating lines, bright stars and other optical wonders. That is not a description of anything like the inside of the eye, so no, you cannot see any structure with that kaliedescopic ripoff. The only way you could see the inside of your own eye is to have someone take a photo of it: check out: http://www.folsomeye.com > My dusty 1998 Edmund Scientifics catalog, there is an item called an >eyescope. [quoted text clipped - 10 lines] > > >, > The only > way you could see the inside of your own eye is to have someone take a > photo of it: Dear Dr. Stacy, Not exactly true. There are entoptic phenomena where the eye can see within the eye. For example, a patient having a slit lamp exam can momentarily see his retinal vasculature. Or the observation of white cells against a blue (say sky) background has been documented. And there is the blue arcs phenomena (Purkenje) that one doctor has proposed (patented) a means of observing glaucoma changes. Etc. So....depends how you define see. Don W On 3/2/07 7:49 AM, in article 1172850549.199160.60840@s48g2000cws.googlegroups.com, "Don W" <dwilgus@prodigy.net> wrote: >> , >> The only [quoted text clipped - 12 lines] > > Don W Sometimes, I see the vasculature spontaneously without trying. I do not remember the exact conditions. Bill -- Fermez le Bush--about two years to go. > > Don W > > Sometimes, I see the vasculature spontaneously without trying. I do not > remember the exact conditions. Well, if for some reason the light may enter the eye so as to be reflected off the inside of the eye so as to move the shadow off its normal position, then the "new" shadow can be seen. The text Bennett and Rabbett, "Clinical Visual Optics" shows this in one of their figures. But the conditions have to be just right. Like not too much "other" light. Don W. > Well, if for some reason the light may enter the eye so as to be > reflected off the inside of the eye so as to move the shadow off its > normal position, then the "new" shadow can be seen. The text Bennett > and Rabbett, "Clinical Visual Optics" shows this in one of their > figures. But the conditions have to be just right. Like not too much > "other" light. It's easy to do with a penlight. Just wiggle it while holding it close, pointing at the sclera. The image you obtain this way is called "Purkinje's tree." -MT >>, >> The only [quoted text clipped - 12 lines] > > Don W No, it's exactly true, at least with today's available instrumentation. Entoptic phenomena are certainly "visible" in the sense that you can "see" the shadows of structures within the eye, but you are certainly not viewing the structures themselves (the floaters and the blood vessels) as you would be able to do with an ophthalmoscope, a fundus camera, or directly on the dissection table. It's just like another entoptic phenomenon, the phosphenes of digital pressure on the globe. You are not seeing the physically stimulated retinal receptors that are causing the appearance of the lights, just the projected image of them in space. w.stacy, o.d. > My dusty 1998 Edmund Scientifics catalog, there is an item called an >eyescope. [quoted text clipped - 8 lines] > >bill I have an eyescope from Edmund Scientific. I bought it out of curiosity and not as a substitute for an ophthalmologist's exam. It contains a battery and light bulb, a parabolic mirror, and a very small lens. They claim that it forms a virtual image of the inside of your eye. An instruction booklet shows typical images of healthy and unhealthy eyes. They state that it is not a diagnostic tool, but a means of self-examination, like a mirror. I can see lots of floaters in my eyes. Also I can see the scleral buckle in one eye from a 1976 operation for retinal detachment. I cannot see the optic nerve. The images do not have enough resolution to see any detail. Since I'm not a doctor, I cannot interpret what I have seen any better than I've stated. Uncle Uncle, Does the eyescope view the eye directly, or are you looking at a projection of the eye, similiar to this: http://www.exo.net/~pauld/summer_institute/summer_day2the_eye/seeing_your_retina.html thanks, bill > > My dusty 1998 Edmund Scientifics catalog, there is an item called an > >eyescope. [quoted text clipped - 24 lines] > > Uncle >Uncle, > Does the eyescope view the eye directly, or are you looking at a [quoted text clipped - 3 lines] >thanks, >bill It most likely works on the same principle as your above link shows. The eyescope surface that goes in front of the eye is dull black surrounding the light, which is very small and dim. So the image must be formed on the dull black surface. Uncle > >Uncle, > > Does the eyescope view the eye directly, or are you looking at a [quoted text clipped - 10 lines] > > Uncle I was under the impression that the upper surface (of the Edmund Scientific device) was a reflective concave mirror. And it used that kind of optics for the viewing. Truth?? Don W >> >Uncle, >> > Does the eyescope view the eye directly, or are you looking at a [quoted text clipped - 16 lines] > >Don W Today I opened the eyescope for the second time in several years (The first time was to replace the batteries). It is a flashlight with two AA cells. The parabolic mirror is a flashlight reflector and it has a flashlight bulb. I removed the front section which goes near the eye. This is a piece of thin metal with a flat black finish on the outside. It is elliptical with dimensions of 1.2 by 1.6 inch. In the center of this section is what appears to be a tiny lens. On the inside of this section there is a cup-shaped piece that I think shields the lens from the bulb filament but allows the surrounding light from the parabolic mirror to hit the lens. I say this because when I held the front section up to a ceiling light I could see nothing through the lens. Without this front section the eyescope is a small flashlight and is as bright as you would expect a small flashlight to be. As far as I can tell, the purpose of the lens is to concentrate the light down to a point source. In principle, you could take an ordinary flashlight and cover the front with black construction paper with a tiny hole in the center. If the hole is small enough, you get the same effect, whatever it is, as the eyescope gives. So the parabolic mirror is merely a flashlight reflector, and the image you get is the same as you see with the small dim flashlight in a dark room, as described in the earlier link. The eyescope is a more refined way to get the same phenomenon. Whether I really saw my scleral buckle I can not be sure. But the image in the operated eye looks a lot more complicated than the image in the other eye. That's all I want to say about the eyescope. Uncle > Whether I really saw my scleral buckle I can not be sure. But the > image in the operated eye looks a lot more complicated than the image > in the other eye. The other problem with "seeing" your scleral buckle is that the buckle resides outside the sclera, which is completely opaque. Even with an ophthalmoscope, we cannot see the buckle itself, only the "humped up" chorio-retina beneath the buckle. > Today I opened the eyescope for the second time in several years > (The first time was to replace the batteries). It is a flashlight with [quoted text clipped - 24 lines] > in the other eye. > That's all I want to say about the eyescope. Thanks for the description. I did find thru a Google search that the Eyescope is still being sold, for something like $50 (two variations of it, I noted). Hard to believe that just a pinhole source of light could be pitched for such a price. Don W > I can see lots of floaters in my eyes. Also I can see the scleral > buckle in one eye from a 1976 operation for retinal detachment. I > cannot see the optic nerve. The images do not have enough resolution > to see any detail. I don't doubt you can see floaters, as anyone with them can plainly see them without the help from any device at all. But you cannot see your own scleral buckle with that piece of junk, that's for sure. You're seeing something I'm sure, but it sure as hell isn't the buckle. w.stacy, o.d. On 3/2/07 10:37 AM, "Salmon Egg" <salmonegg@sbcglobal.net> wrote: > Sometimes, I see the vasculature spontaneously without trying. I do not > remember the exact conditions. I rediscovered one situation for seeing this vasculature. If I am in a bright light and close my eyes or go into a darkened room I notice a network that I take to arise from blood vessels in the retina. Bill -- Fermez le Bush--about two years to go. I have numerous retinal problems, and have been using Edmund's eyescope for over 10 years. I also have a scleral buckle, and I am not sure if I am seeing it or not. But I do see a thin black line that encircles that eye, and it is not on the unoperated eye. I also can see my cataract which shows as a solid black circle, drusen, which appears as small yellow circles, and macula edema which shows as reddish circles. I once saw a jagged black line, which my doctor confirmed was a retinal tear. I find the eyescpope an invaluable tool in aiding myself to check the health of my own eyes, and am disappointed to hear they no longer sell it. > I have numerous retinal problems, and have been using Edmund's eyescope for > over 10 years. [quoted text clipped - 10 lines] > I find the eyescpope an invaluable tool in aiding myself to check the > health of my own eyes, and am disappointed to hear they no longer sell it. Still being sold. Check Google for "eyescope". There are some outfits that do. Don W > I have numerous retinal problems, and have been using Edmund's eyescope for > over 10 years. > > I also have a scleral buckle, and I am not sure if I am seeing it or not. > But I do see a thin black line that encircles that eye, and it is not on the > unoperated eye. What exactly do you mean by "encircles that eye"? Do you mean you see your eye in space with like a saturn's ring around it? What detail of the eye you are seeing inside that ring makes you think it's your eye? > I also can see my cataract which shows as a solid black circle That is not a catract for sure. Cataracts don't come in circles. Ever. , drusen, > which appears as small yellow circles, Well it's true that drusen can be yellowish, but again, they are not circles but spots. and macula edema which shows as > reddish circles. You are not seeing macular edema. Again, that comes as a spot, not a circle. I once saw a jagged black line, which my doctor confirmed > was a retinal tear. You wouldn't need an eyescope to see such an event, even if it were possible. Retinal tears are often visible to the recipient without any device at all. > I find the eyescpope an invaluable tool in aiding myself to check the > health of my own eyes, and am disappointed to hear they no longer sell it. I'm afraid you are seeing things. Dr. Stacy, I have been reading this newsgroup for quite a while now,and very rarely post anything, and have always respected your opinion on things. However, I am definitely not "seeing things". The surgeries I have had correspond to what I see within the eyescope. I wish I could draw a picture of what I see. In reference to the "buckle", I see a light gray circle with a dark black boundary around the entire circle. When my eye is dilated, I can see more of the gray circle beyond the black boundary. However, this part is a darker, more splotchy gray color. It almost looks like the surface of the moon, while the inner gray circle is relatively smooth. I also have an IOL implant, so maybe this is what I am seeing instead. I do know on the unoperated eye, the entire gray circle is smooth looking with no black boundary separating it. You are correct in that the cataract, drusen, and edema show as spots, and not circles. I should not have used that term. The drusen though has a definite black border around the spots with a yellow center. I also see floaters, and long strings of what look like pearls in the unoperated eye. I am aware you can also see floaters without the aid of the eyescope, but it does make it a lot easier to spot them. Of course, I am not a medical professional, nor a master in understanding optics. And, I certainly don't have the imagination to make up these things. I was only trying to help the original poster and tell of my experience with the eyescope. Kathy >Dr. Stacy, > [quoted text clipped - 3 lines] >what I see within the eyescope. I wish I could draw a picture of what I see. > You should be able to draw it if you can view it, even if only roughly. >In reference to the "buckle", I see a light gray circle with a dark black >boundary around the entire circle. When my eye is dilated, I can see more of [quoted text clipped - 5 lines] >boundary separating it. > I would bet you are seeing a reflection of the edge of the IOL. >You are correct in that the cataract, drusen, and edema show as spots, and >not circles. I should not have used that term. The drusen though has a [quoted text clipped - 3 lines] >does make it a lot easier to spot them. > It may enhance your ability to see floaters but it could also be that you are seeing reflections of debris in your tear layer. Hard to tell from the description of the device. >Of course, I am not a medical professional, nor a master in understanding >optics. And, I certainly don't have the imagination to make up these things. >I was only trying to help the original poster and tell of my experience with >the eyescope. > Sorry if I was abrasive, but see my next post. Kathy, Forgot to ask the last time. Is there any sort of a diagram of the optics that might come with your eyescope? Just exactly how did your doctor comment on your observations? Don W Don, The booklet that came with it does not have a diagam of the optics, but I can tell you how it describes how it works. This is taken directly from the booklet. "The Eyescope is a specially designed optical pinhole and light diffuser incorporating parabolic mirror and a lens light inside of it. The light from the Eyescope is so tiny that it is equivalent to starlight, about half the strength of a phosphorescent night light". I once brought it in for my retinal specialist to see it. This was several years ago, so I hardly remember what he said. But, I do remember him saying it projects an image of the different layers of the eye. He also told me to continue using it to check my own eyes and to make an appointment if I noticed anything different. I see him every two months as it is, so he must feel it has some credibility. Kathy >I once brought it in for my retinal specialist to see it. This was several >years ago, so I hardly remember what he said. But, I do remember him saying [quoted text clipped - 3 lines] >feel it has some credibility. > I doubt very much he said that. Unless he's a quack, and I doubt that too. Maybe he was just humoring you. > >I once brought it in for my retinal specialist to see it. This was several > >years ago, so I hardly remember what he said. But, I do remember him saying [quoted text clipped - 5 lines] > I doubt very much he said that. Unless he's a quack, and I doubt that > too. Maybe he was just humoring you. Gosh! It must be wonderful to be so certain of things in life... After 40 years as an engineer, I still haven't achieved the acme of knowledge, that I have nothing to question or learn. > > [quoted text clipped - 17 lines] >I have nothing to question or learn. > Hey it's pretty easy to be certain of some things in this business. If that device really worked, don't you think all of us in the profession would have one so we could see inside our own eyes? Especially at the price offered! That way we wouldn't have to resort to shining a retinoscope or ophthalmoscope at our own eyes via a mirror (hard to do and the view is terrible).... Yep, some things are easy, and being certain of those doesn't mean one doesn't question or learn... > Yep, some things are easy, and being certain of those doesn't mean one > doesn't question or learn...- Hide quoted text - Well, putting aside the lighting question (of course, a big aside) you would agree it is possible to construct an concave mirror that when looked into at a certain distance, allows the retina to be focused back (reflected) onto the retina. Say move the focal point to get the biggest image of the retina through the pupil. Don W . >>Yep, some things are easy, and being certain of those doesn't mean one >>doesn't question or learn...- Hide quoted text - [quoted text clipped - 7 lines] >get the biggest image of the retina through the pupil. > I don't know why it would have to be concave, as a flat mirror should work just fine. But you hit on the problem, which is the amount of light it would take to accomplish the feat would be huge and would dazzle the retina so much the secondary reflected image would be lost. If you've ever had a fundus photo taken, you could appreciate the amount of light required to even pick up a primary fundus image by a camera. If you haven't, just bring a flash camera within an inch of your eye, look at the strobe and fire it off. > > Well, putting aside the lighting question (of course, a big aside) > >you would agree it is possible to construct an concave mirror that [quoted text clipped - 10 lines] > If you haven't, just bring a flash camera within an inch of your eye, > look at the strobe and fire it off. Well, the mirror would be concave to move the focal point somewhere at the center of the pupil. (Longitudinal axis). Otherwise one would be contrained by a flat mirror to the lesser view provided only by the area of the pupil. Not true about the "huge amount of light". There is one paper I had come across where the author (an eye doctor, I believe) discusses the construction of a homemade ophthalmoscope. Made out of a couple of AAA's and a small penlight bulb, incased in a rolled one sided reflective paper tube, plus an angled mirror with pinhole . He saw quite a few details, macula, optic nerve, of his friends, cats, as he reported. One of the letters commenting on the paper said they couldn't wait for his design of a homemade sigmoidoscope. Thought that was pretty cruel at the time. Don W > Well, the mirror would be concave to move the focal point somewhere > at the center of the pupil. (Longitudinal axis). Otherwise one would > be contrained by a flat mirror to the lesser view provided only by the > area of the pupil. True, but it would at least be in focus. Constructed as you suggest will put the image out of focus on the retina. > Not true about the "huge amount of light". There is one paper I had > come across where the author (an eye doctor, I believe) discusses the [quoted text clipped - 3 lines] > quite a few details, macula, optic nerve, of his friends, cats, as he > reported. Sorry, but it would take a huge amount to directly view YOUR OWN fundus details, because you have to take that dim retinal reflex and bounce it back onto the viewer's own retina which is simultaneously being dazzled by the main light source. No hope of seeing anything but the bright light. The home made ophthalmoscope is only good (if I can allow that term) when viewing SOMEONE ELSE'S fundus. Well, OK, I am convinced that the "Eyescope" as presently still sold, consists of supplying a pinhole light source backed up by a parabolic mirror. And the images produced are due to the internal reflections and refractions of the eye (termed entoptic). These images are described in separate chapters in Helmholtz's "Treatise on Physiological Optics" (Vol 1, Chapt 15) and the above mentioned Bennett (Chapt 22). These references include a complete chapter on these effects and what produces them. Some of the advertising of what the Eyescope can do borrows exactly from Helmholtz's descriptions. As to people using this device and "seeing things", they are probably seeing the same things that Helmholtz saw and chose to document. As to the diagnostic merit of these observations, probably debatable. Especially here. Don W. On 3/5/07 10:57 AM, in article NKZGh.9386$Jl.9200@newsread3.news.pas.earthlink.net, "Kathy" <auriga24@REMOVEmindspring.com> wrote: > I once brought it in for my retinal specialist to see it. This was several > years ago, so I hardly remember what he said. But, I do remember him saying > it projects an image of the different layers of the eye. He also told me to > continue using it to check my own eyes and to make an appointment if I > noticed anything different. I see him every two months as it is, so he must > feel it has some credibility. It also gives you something to do and keeps you off the street. You probably do not annoy him as much as compared to not occupying your time. That way. Bill -- Fermez le Bush--about two years to go. Wow. That hurt. I have never claimed that I see the exact image a doctor sees when he looks into my eyes. All I attempted to do was to explain that there are some things within the eye that are easily distinguishable using the eyescope. I thought I was helping. Apparently, that is not the case. I have been told that I am seeing things, that I am a liar, my doctor is a quack, and that I am annoying. For the record, I see one of the most respected retinal specialists in the country. I have had just about every retinal disease you can think of along with a handful of surgeries to correct them. My doctor tells me I am somewhat of an unusual case in that I acquired these problems at a relatively young age. It was my hope that I could occasionally answer someone's questions here from a patient's point of view. The eyescope thread was one where I thought I could lend some insight with my own experience with it. I truly do no understand why my post was met with such hostility, but I will not make the mistake of posting on this newsgroup again. Thanks guys for running me off. Kathy |
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