 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Medical Forum / General / Vision / October 2005reviving the topic "thousands of floaters"
http://groups.google.com/group/sci.med.vision/tree/browse_frm/thread/1cad9960988 c2fe2/a031aa9cbcfd279a So where are the explanations already? I've seen these also, but they shouldn't be called floaters. They are best described as a shower of clear, tailed speckles over a small splotch of sight. They start at a point, fly out mostly straight but sometimes bent, then fade out. The source is usually off-middle of the splotch. If they could make a sound, I'd imagine high-pitched rays. They show up when I look in the low afternoon sky. -Aut The dark ones are simply particles of tissue that can range from transluscent (vitreous) to semi-opaque (blood) floating in the posterior chamber of the eye. The lighted ones (photopsia) are probably neuro/vascular noise that could be anywhere from the retina to the occiptital cortex. The treatment is the same. Ignore. w.stacy, o.d. > http://groups.google.com/group/sci.med.vision/tree/browse_frm/thread/1cad9960988 c2fe2/a031aa9cbcfd279a > [quoted text clipped - 8 lines] > > -Aut > So where are the explanations already? Could this be it? http://psychcentral.com/psypsych/Blue_field_entoptic_phenomenon -MT > Could this be it? > > http://psychcentral.com/psypsych/Blue_field_entoptic_phenomenon Thanks so much! But it's http://en.wikipedia.org/wiki/Blue_field_entoptic_phenomenon. That's it. I had remembered some self-test of HIV by seeing how many white blood cells were flowing through the sight's field, but didn't have a size to pin them on. I'd been thinking that the floaters were the cells. William Stacy is a liar who has reading problems. Seeing sparks may be a sign of a failing retina. -Aut > http://en.wikipedia.org/wiki/Blue_field_entoptic_phenomenon. That's > it. I had remembered some self-test of HIV by seeing how many white > blood cells were flowing through the sight's field, but didn't have a > size to pin them on. I'd been thinking that the floaters were the > cells. It was the first time I'd heard the Scheerer effect called "floaters." 99.99% of "floater" discussions are about vitreous opacities. -MT Well I've been called a lot of things but usually liar isn't one of them. In the context of the thread "thousands of floaters" and the discussion of central photopsia, I am aware of the theory that leukocytes are the cause, and have generally dismissed this theory because of the size of such cells is too small to be visualized by the human retina. How do you explain that a cell having a diameter of about 10 microns can be detected by the retina when it is lying close to the retina? Anyway, I admit to swimming upstream on this one. BTW this blue field phenomenon has nothing at all to do with retinal detachment risk. The "sparks" preceeding retinal detachment are huge by comparison, and way more dramatic. w.stacy, o.d. > > [quoted text clipped - 16 lines] > > > How do you explain that a cell having a diameter of about 10 microns can be detected by the retina when it is lying close to the retina? You don't buy Applegate's computation given (for example) in that before mentioned patent 5016643?? Don W. OK I'm now ready to concede that the "flying corpuscles" seen in blue field entoptoscopic observations are indeed most likely due to occasional leukocytic interruptions in the relatively opaque RBC stream of the retinal capillaries. It's a fascinating subject with promising diagnostic potentials in conditions that affect microvasculature of the eye, like diabetes, glaucoma, etc. w.stacy, o.d. > > How do you explain that a cell having a diameter of about 10 microns > can be detected by the retina when it is lying close to the retina? [quoted text clipped - 6 lines] > > > Well I've been called a lot of things but usually liar isn't one of > them. In the context of the thread "thousands of floaters" and the > discussion of central photopsia, I am aware of the theory that what discussion? > leukocytes are the cause, and have generally dismissed this theory > because of the size of such cells is too small to be visualized by the > human retina. How do you explain that a cell having a diameter of about > 10 microns can be detected by the retina when it is lying close to the > retina? The cells could be pushing against the retina? When I had a lot of free time, I took it to develop a whole new set of measures, starting with length. I marked off various scratches on a stainless steel ruler and eventually estimated that the thinnest line I could see, when shined upon, was about 1/72 mm or 14 or 15 microns. > Anyway, I admit to swimming upstream on this one. BTW this blue field > phenomenon has nothing at all to do with retinal detachment risk. The > "sparks" preceeding retinal detachment are huge by comparison, and way > more dramatic. I know it doesn't. How do the sparks compare to those from hupertension, poking the optic nerve when the head moves around when looking up or going into a room? -Aut > The cells could be pushing against the retina? This theory I rejected out of hand when I first saw it a couple of years ago, because the nano-pressures involved intuitively seem hardly sufficient to mechanically stimulate a rod or cone. I now believe that it is simply a matter of ordinary light transmission by the relatively transparent leukocytes, which does make sense. w.stacy, o.d. > > The cells could be pushing against the retina? > [quoted text clipped - 3 lines] > it is simply a matter of ordinary light transmission by the relatively > transparent leukocytes, which does make sense. Diffraction helps too. Ever heard of a Fresnel zone plate? -Aut > Diffraction helps too. Ever heard of a Fresnel zone plate? Never heard of that, but I would think that diffaction would not be particularly helpful, since it takes relatively finely focused light and spreads it out over rings or lines. The "flying corpuscles" are very distinct, and relatively sharply defined, which is one reason I accept the WBC theory. Those retinal capillaries are right on and in the retina. One thing that still bothers me is why the flashes are white. If blue light is used to bring them out, where does white come from? I've heard the notion that maybe they are fluorescing, but I doubt that. I guess a very bright flash of blue against a dimmer blue background could be perceived as white. w.stacy, o.d. Diffraction doesn't need focused light, only fine structures. A zone plate is like a bunch of pinholes--more like pinrings--that confocally magnify light when the magnifier can be any thinness. I don't know what flashes you're talking about. The streaks or shower is not flashy. It seems the blue light goes into the fringes. -Aut I don't think zone plates notion applies to this thread, as they require concentric ring apertures that don't exist in the eye. The flashes that have been discussed in this thread are the "blue field flying corpuscles" variety. These are indeed "flashy". I'm not sure what your last sentence means. w.stacy, o.d. > Diffraction doesn't need focused light, only fine structures. A zone > plate is like a bunch of pinholes--more like pinrings--that confocally [quoted text clipped - 4 lines] > > -Aut > I don't think zone plates notion applies to this thread, as they require > concentric ring apertures that don't exist in the eye. Yet small objects still bend liht around them. > The flashes that have been discussed in this thread are the "blue field > flying corpuscles" variety. These are indeed "flashy". I'm not sure > what your last sentence means. The streaks are not flashy, but streaky. Sounds like you're referring to ordinary vitreous floaters. BTW all the grammar corrections are not needed. It's acceptible on news groups to be a bit sloppy as long as your point gets across and makes cents. w.stacy, o.d. >>I don't think zone plates notion applies to this thread, as they require >> concentric ring apertures that don't exist in the eye. [quoted text clipped - 6 lines] > > The streaks are not flashy, but streaky. > BTW all the grammar corrections are not needed. It's acceptible on news > groups to be a bit sloppy as long as your point gets across and makes cents. These private practice doctors! All the time grubbing after money! :-) (making the point that although most spelling and grammar errors are obvious, some do in fact distort the meaning) re money grubbing: the double entendre was intended, of course. this time... w.stacy, o.d. > re money grubbing: > > the double entendre was intended, of course. > > this time... My wife and I are a little anal retentive when it comes to spelling, grammar and clear writing. We try to keep it under control, though. My wife is currently battling the local school board over this, though. Their minutes (and some other documents) have spelling errors, grammar errors, sentences that make no sense whatsoever, and other sentences that are just plain wrong. All this could be forgiven, possibly, except that they all state that the number one goal of the entire school district is literacy, specifically writing. My wife has tried to handle this outside of board meetings, but she just gets ignored. When she brings it up at board meetings, she is told that nobody in the district office has time to proofread, that it is unimportant and that nobody cares anyway. This is a legal document, and although 99.9% of the time it will be totally forgotten once read, it *is* the official and only record of what was decided. Occasionally things go to court, and not only it is an embarrassment to have these errors, the court will rely on what it written to determine the final decision. If the parties disagree as to what is meant, then somebody has to determine what the original intent was. >My wife and I are a little anal retentive when it comes to spelling, >grammar and clear writing. We try to keep it under control, though. > > I can appreciate that. My daughter is now a school teacher and I have a hard time accepting things like: "That boy is *so* not going to graduate"... But language evolves, as it doing on s.m.v. I've gotten over it. w.stacy, o.d. >>My wife and I are a little anal retentive when it comes to spelling, >>grammar and clear writing. We try to keep it under control, though. [quoted text clipped - 7 lines] > >I've gotten over it. LOL... gotten.. you 'mericans and your weird words... > LOL... gotten.. you 'mericans and your weird words... I wasn't gonna reply but this thread is so far off it's original topic, one more aint gonna make no differ'nce. Aint "gotten" a sure enough good word, bein' a past participle of "get"? I'm gitten outta here... w.stacy, o.d. it's -> its grammar police -> boring, wasteful of bandwith, unwanted, unappreciated, endangered species >it's -> its > > bandwith -> bandwidth > bandwith -> bandwidth Do you have some other purpose in life other than to waste internet bandwidth, contributing nothing to actual discussion? Perhaps you're on a quest to be hired as The Internet Proof-Reader. Have some respect for the fact that is a global forum and not everyone is perfectly fluent in English or are expert typists. Geez, another looney! > Do you have some other purpose in life other than to waste internet > bandwidth, contributing nothing to actual discussion? Perhaps you're on > a quest to be hired as The Internet Proof-Reader. Yes, look elsewhere. > Have some respect for the fact that is a global forum and not everyone > is perfectly fluent in English or are expert typists. > > Geez, another looney! So you would rather they keep making mistakes. You want people to live in ignorance. /You/ are the loony. -Aut Editors make everyone else look more literate than they really are. The "glassy" floaters are not streaky, but drifty. > One thing that still bothers me is why the flashes are white. If blue > light is used to bring them out, where does white come from? I've heard > the notion that maybe they are fluorescing, but I doubt that. I guess a > very bright flash of blue against a dimmer blue background could be > perceived as white. Of the papers that I have on the "blue field entopic phenomenon", I cannot seem to get the specific answer as to why those flashes of the leukocytes are white against a (relatively pure) blue background. I don't think they are fluorescing since one paper used quinacrine to render the leukocytes fluorescent in an experiment on a bat in this blue field. Don W. > Of the papers that I have on the "blue field entopic phenomenon", I > cannot seem to get the specific answer as to why those flashes of the > leukocytes are white against a (relatively pure) blue background. I don't > think they are fluorescing since one paper used quinacrine to render the > leukocytes fluorescent in an experiment on a bat in this blue field. If leucocytes are more transparent than RBCs, they'd form gaps in the otherwise opaque blood column. -MT >> Of the papers that I have on the "blue field entopic phenomenon", I >> cannot seem to get the specific answer as to why those flashes of the [quoted text clipped - 5 lines] > If leucocytes are more transparent than RBCs, they'd form gaps in the > otherwise opaque blood column. Yes, also from Applegate's 5,640,220 patent, ....... "The capillaries of the retina are normally filled with red red blood cells that move in a single file. Occasionally, this motion is interrupted by a white blood cell or a plasma gap. Since the blue light is almost totally absorbed by the hemaglobin contained in the red blood cells, light reaches the photoreceptor only when it is not passing through the red blood cells". That's from paragraph 1.2 of his patent. But I also don't see the reason for the "white" effect. Don W. > But I also don't see the reason for the "white" effect. Against a blue background, anything brighter and less saturated will seem "white" by comparison. These gaps aren't brighter than the background, but the photoreceptors under a blood column would have to be a little dark-adapted, relative to those that are fully exposed. -MT I have a couple of ideas on this. One is that the receptors are relatively "dark adapted" under the shadow of the capillary, and the sudden stimulus is so great as to overpower the color phenomenon, just as the sun looks white when you glance at it, when it is probably more orange. The other idea is that it's only rods that are so stimulated, and of course, they are monochromatic. w.stacy, o.d. > Of the papers that I have on the "blue field entopic phenomenon", I cannot > seem to get the specific answer as to why those flashes of the leukocytes > are white against a (relatively pure) blue background. I don't think they > are fluorescing since one paper used quinacrine to render the leukocytes > fluorescent in an experiment on a bat in this blue field. >> One thing that still bothers me is why the flashes are white. If blue >> light is used to bring them out, where does white come from? I've heard [quoted text clipped - 9 lines] > > Don W. > Well I've been called a lot of things but usually liar isn't one of > them. In the context of the thread "thousands of floaters" and the > discussion of central photopsia, I am aware of the theory that what discussion? > leukocytes are the cause, and have generally dismissed this theory > because of the size of such cells is too small to be visualized by the > human retina. How do you explain that a cell having a diameter of about > 10 microns can be detected by the retina when it is lying close to the > retina? The cells could be pushing against the retina? When I had a lot of free time, I took it to develop a whole new set of measures, starting with length. I marked off various scratches on a stainless steel ruler and eventually estimated that the thinnest line I could see, when shined upon, was about 1/72 mm or 14 or 15 microns. > Anyway, I admit to swimming upstream on this one. BTW this blue field > phenomenon has nothing at all to do with retinal detachment risk. The > "sparks" preceeding retinal detachment are huge by comparison, and way > more dramatic. I know it doesn't. How do the sparks compare to those from hupertension, poking the optic nerve when the head moves around when looking up or going into a room? -Aut > So where are the explanations already? > [quoted text clipped - 4 lines] > splotch. If they could make a sound, I'd imagine high-pitched rays. > They show up when I look in the low afternoon sky. If they are white blood cells, you should not be seeing them in the central 5 degrees of vision (of course, in a normal eye). Only in a ring around that area. Some researchers have said that black dots may appear because of the bunching up of theses cells behind the white ones. You can calibrate the vision angle by holding your fist at arm's length.... that's approximately 10 degrees. It would be interesting to see, if any way, your "speckles" are in any way sync'd to the pulse. Don W. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.