Snellen and glasses - Printable Version +- Eyesight Improvement Forum (https://www.iblindness.org/forum) +-- Forum: General Discussion (https://www.iblindness.org/forum/forumdisplay.php?fid=4) +--- Forum: Bates Method (https://www.iblindness.org/forum/forumdisplay.php?fid=5) +--- Thread: Snellen and glasses (/showthread.php?tid=394) |
Snellen and glasses - Otter - 05-31-2007 If you can see the snellen at 20/20 with glasses, could your eyesight be worse and you not know it? In other words, does diopters change along with distance vision? Sry its just hard for me to explain this. Re: Snellen and glasses - Otter - 05-31-2007 wait i know how to explain it now. Does diopters worsen/improve along with distance vision? Re: Snellen and glasses - otis - 05-31-2007 Dear Otter, Let me simplyiy the eye's behavior, and the proven effect of a -3 diopter lens on all fundamental eyes. A refractive STATE of zero is considered normal. So we check to see if a -3 diopter lens is even SAFE, i.e., does not produce a negative refractive STATE, or "cause nearsightedness", if you will. This is a critical scientific experiment, because the majority-opinion ODs ASSUME the minus has NO EFFECT. The scientific TRUTH? You place a -3 diopter lens on the fundamental eye, and in less than two months the eye will change its STATE by -2 diopters. Thus, the eye "follows" the minus as a fundamental principle. If this were done to a human, the result would be 20/140 vision, in an eye that had a refractive STATE of zero to start with. Thus while the minus "works" and "impresses", it is a "solution" that creates a secondary-problem. As Bates pointed out -- and is now proven, you should see methods to avoid the minus, and PASS the DMV test. Thus avoiding the minus. To me this resolves the issue on a scientific level. Otis Re: Snellen and glasses - otis - 05-31-2007 Dear Otter, I am not certain how to answer your question. But keep in mind what is proven about the effect of a strong minus on the eye's refractive STATE. Otter> If you can see the snellen at 20/20 with glasses, could your eyesight be worse and you not know it? Otis> The normal process is to put up a Snellen, and have you read at say 20/70, or so. Minus lenses are placed in front of your eyes, until one is found to clear the 20/20 line. You question is not clear to me. In other words, does diopters change along with distance vision? Sry its just hard for me to explain this. Otis> Your eyes must AUTOMATICALLY change their power when you look from distance to near. The amount of change is directly a result of what you look at. Best, Otis Re: Snellen and glasses - Kazekage - 06-01-2007 Quote:Does diopters worsen/improve along with distance vision? Yes, this is called accommodation. I think diopters move in a negative state when seeing objects up close, and in a positive state when seeing distance objects. Accommodation is a mechanism the eye uses to focus at different distances. Quote:Accommodation is the process by which the eye increases optical power to maintain a clear image (focus) on the retina. The principal focusing ability of the (terrestrial) eye is due to the difference in refractive index between air and the curved cornea, but the variable curvature of the lens allows for an additional adjustment. This varies from a maximum of over 15 diopters in an infant to only about 1.5 diopters in a person 70 years old, as the lens becomes less flexible with age. Some theories about how it works: Quote:- Helmholtz - The most widely held theory of accommodation is that proposed by Hermann von Helmholtz in the middle of the 19th century. When viewing a far object, the circularly arranged ciliary muscle relaxes causing the lens zonules and suspensory ligaments to pull on the lens, flattening it. The source of the tension is the pressure that the vitreous and aqueous humours exert outwards onto the sclera. When viewing a near object, the ciliary muscles contract (resisting the outward pressure on the sclera) causing the lens zonules to slacken which allows the lens to spring back into a thicker, more convex, form. - <!-- m --><a class="postlink" href="http://en.wikipedia.org/wiki/Accommodation_%28eye%29">http://en.wikipedia.org/wiki/Accommodation_%28eye%29</a><!-- m --> So basically no one is exactly sure, the dispute is ongoing... I think it's probably a mixture of Bates and Helmholtz ??? maybe Re: Snellen and glasses - otis - 06-01-2007 Dear Otter, Do not get "lost in the sauce". Go back to baics. Bates said that the entire eye "accommodates" -- for the long-term. I think we should concentrate on THAT issue, and not get "lost" in these detailed "arguments". As Kaze said, the eye accommodates, and the DETAILS of HOW it does it, and be left for future experiments. The main issue is that Bates was right, that you could clear your Snellen -- if you WORKED AT IT. You have the elements of success. Now the difficulties: 1. Any of these preventive methods are an intrusion in your life. 2. This intrusion can not be prescribed. You must do it youself. 3. If you are successful, you will see you Snellen clear from 20/80 to 20/40 or better. 4. It will take some time to do it. But on the positive side, experts like Dr. Jacob Liberman have done it TO HIMSELF. And I think that is the real power of Bates. Otis |