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Medical Forum / General / Vision / November 2005Pinhole glasses good for computer work?
Hi all. I'm shortsighted programmer, wearing glasses with -1.0ph/0.5cyl dioptry on each eye, and after only 2 hours of working in from of my LCD, my eyes hurt quite a bit. In fact, they hurt all the time, because they don't have time to rest properly, even after night sleep. Now, I heard about this pinhole glasses. I've read a bit about how they work, and I know they will not improve my eyesight, but I'm curious whether they will put away strain on my eyes when I work in front of computer? I know they reduce peripheral vision, but I don't need peripheral vision when I work with computer. I know they reduce brightness, but I have enough of brightness (probably too much) from my LCD, so it doesn't bother me also. So, could it do me good? And most importantly, can they harm my eyes somehow? Regards, Vjeran > Hi all. > [quoted text clipped - 17 lines] > Regards, > Vjeran They won't do any harm to your eyes, so by all means give them a go for a few hours. You'll probably find them so frustrating that you'll give up on them before long. Do you currently wear your distance vision specs while using the computer? If so, try taking them off. Also, try eye drops (artificial tears). I assume you've had a thorough eye test recently to exclude any other causes of sore eyes. Dom why would you even need glasses for the computer? If your a -1 and sit 1 meter(or closer) you will see better without glasses than with! I am about a -5 but wear -3.25 glasses for the computer and my eyes have never felt more relaxed! You dont even need to wear your glasses much except for driving or watching movies Doctor told me that even if I don't have any problems seeing things at close (because I am shortsighted), I should wear glasses constantly, because adaptation of eye when taking glasses off is not healthy... > why would you even need glasses for the computer? If your a -1 and sit > 1 meter(or closer) you will see better without glasses than with! I am > about a -5 but wear -3.25 glasses for the computer and my eyes have > never felt more relaxed! You dont even need to wear your glasses much > except for driving or watching movies sorry thats not true. In fact using glasses to see from near when you can see fine without will make vision worse, see pseudomyopia which eventurally will increase enlongation of the eye. You have the gift of seeing well from near without glasses, use it! >Hi all. > [quoted text clipped - 17 lines] >Regards, >Vjeran Why don't you try. They come with different pinhole sizes and patterns. Usually they are the ultima ratio for people with 20 diopters :-) For computer work you need glasses with varying focus. They are expensive and not every optician can make them. In fact, many sell glasses from cheap manufacturers and do not know how to handle varying focus glasses at all. You must specifiy "computer work", and explain what it means optically, otherwise they will set the upper part of the glasses to infinity focus, be careful, they are salesmen. Sometimes you need to look around the office, through the upper portion of the glass, that is 5 to 7 m distance, and the shortest distance at the bottom of the glasses will be keyboard, respectively reading a book, that is about 40 cm. Set the center to 70 cm or 1 m distance. I have such glasses and about the same diopters as you. Can work for hours without problems, although not the whole day, need to have a walk in the green sometimes. w. > Hi all. > [quoted text clipped - 17 lines] > Regards, > Vjeran You should see an eye doctor. In my limited experience if there is nothing serious wrong with your eyes all you probably need is eyedrops. > Hi all. > [quoted text clipped - 17 lines] > Regards, > Vjeran Pinhole glasses to improve vision is simply a scam- they do not work. Sometimes dedicated computer glasses with ar (anti-reflective) coating, a gradient tint can be of help. Also, sometimes using artificial tears and looking away from the monitor every 15 minutes or so can reduce eye strain. But the pinholes are simply a waste of money. frank >Pinhole glasses to improve vision is simply a scam- they do not work. This statement is not true, at least not completely. What would "work" mean in such a context. You probably wanted to say, pinholes are not adequate replacements for optical glasses. Of course they work, pinholes are physically functioning optical elements, and can replace a camera lens Enter "pinhole" in Ebay: http://cgi.ebay.at/1-Laser-Pinhole-200-m-fuer-Lochkamera-Bodycap-35mm-83_W0QQite mZ7561755617QQcategoryZ80459QQrdZ1QQcmdZViewItem And when you combine many pinholes you get that: http://cgi.ebay.at/Pinhole-Glasses-Rasterbrille-Case-and-Accessories-NEW_W0QQite mZ7563546356QQcategoryZ32907QQrdZ1QQcmdZViewItem The effect is surprising, it is worth trying from a physics standpoint, and may be useful for certain eye illnesses although I prefer normal glasses :-) w. >>Pinhole glasses to improve vision is simply a scam- they do not work. > [quoted text clipped - 15 lines] > and may be useful for certain eye illnesses > although I prefer normal glasses :-) Pinhole apertures are commonly used in target pistol shooting to improve the depth of field by simultaneously reducing the blur of the front and rear sights as well as the target. There is no conventional transparent lens which can accomplish that. For certain types of eye defects a pinhole lens can provide better visual resolution than a full aperture glass lens. The downside of pinhole lenses is Limited field and reduced image brightness. "glasses" with multiple pinholes were used in some parts of the world long before glass lenses came into use. If the angular spacing of the holes is approximately equal to the angular field of view of one pinhole and in a hexagonal pattern. They give greatly improved resolution, particularly for us old folks who have limited focus accommodation. The "flys eye" effect takes some getting used to. > Pinhole glasses to improve vision is simply a scam- they do not work. > Sometimes dedicated computer glasses with ar (anti-reflective) [quoted text clipped - 3 lines] > looking away from the monitor every 15 minutes or so can reduce eye > strain. But the pinholes are simply a waste of money. They work, and they work really well. My son has a huge cast on his arm. It works really well also. I don't have such a cast, or want one. I'm sure my HMO would refuse to put one on. My wife hurt her foot some time back. She used crutches for a little time. I don't use crutches. I don't want crutches.  SignatureDan Abel dabel@sonic.net Petaluma, California, USA Dear Vjeran, Subject: Pinholes and other alternatives to "relax" accommodation. Sometime long work at a computer terminal creates "pseudo-myopia" a condition where you MIGHT fail the eye-test. In addition to pinhole glasses, you might consider using "relaxing" plus lenses which you can obtain over-the-counter for about $8. Some ODs will prescribe this lens for children on the threshold of myopia, to help them "relax" their eyes. www.myopiafree.com Best, Otis Or he can take his glasses off, save some money and get the same result. A script of -1.00/-0.5 R&L means you are focussed at 80cm so you are pretty well focussed on the screen with no Rx. There is no problem doing this for most people and no adaptation problems either. Try it, you may find it improves things. grant I think you'd better wear an coated glass rather than pinhole glasses. I had a pair of pinhole glass in high school and I know how it works: it just force your eye to use the most sensitive part -- center of your retina where the cell is smaller than usual and the paraxial optical quality is better. As a result, the radiance from the computer starts to hurt your most sensitive part of your eyes... Pinhole glasses is traditionally used for ophthalmologists, to test the vision of your central part of the eye. So, keep using your eye in a healthy way is the best solution. The coating and resin-based glasses will work because the transmission of UV is nearly 0. Eyedrops (artificial tear) will keep your eye cells "breath" and alive. Wish these help. Sincerely, Peng In sci.optics Peng Xi <pxi@purdue.edu> wrote: > I think you'd better wear an coated glass rather than pinhole glasses. I had > a pair of pinhole glass in high school and I know how it works: it just > force your eye to use the most sensitive part -- center of your retina where > the cell is smaller than usual and the paraxial optical quality is better. Err, totally wrong. The image is formed on the same part of the retina, That's why it's not displaced. Pinhole lenses work by masking off the edges of the pupil, which can be significantly abberant. In 'real life', high light levels - such as found outside are supposed to contract the pupil and do this. In low light levels - the expanded pupil and increased light sensitivity are an evolutionary advantage. But, while quite bright, monitors can't produce this amount of light, so the pupil doesn't contract that far, and you get aberrations. Eventually, if monitors remained an important fact of live, we'd evolve. It is possible to somewhat control pupil dilation, but (at least for me) not over long periods. I think Ian omit a fact: what if the pinhole glasses has only 1 hole? Can you see the world as it was without the glasses? You may think that this is kidding, but have you done a simple experiment? The glasses I used has 3 holes on each eye, with totally black plastic glasses to block light. I happen to have no black paper to do this but I did use white paper board to prove my point. I think most of us are near sight and able to do this immediately. Remove your glasses and put a pinhole on your eye, find a target you cannot see clear (even it is monitor screen) and see what can happen? Pinhole glasses cannot work on a very near-sight eye, however, if the hole size is proper (to allow enough light come while still able to limit the light through the pupil), you can see a sharper image. Ian said that the edge of the pupil can be aberrant -- do you think that the random edge of a piece of paper is better than our body which is God's masterpiece? >> the cell is smaller than usual and the paraxial optical quality is >> better. [quoted text clipped - 16 lines] > It is possible to somewhat control pupil dilation, but (at least for me) > not over long periods. In sci.optics Peng Xi <pxi@purdue.edu> wrote: > I think Ian omit a fact: what if the pinhole glasses has only 1 hole? Can > you see the world as it was without the glasses? You may think that this is > kidding, but have you done a simple experiment? No, due to obscuration due to the angle. > The glasses I used has 3 holes on each eye, with totally black plastic > glasses to block light. I happen to have no black paper to do this but I did > use white paper board to prove my point. > I think most of us are near sight and able to do this immediately. > Remove your glasses and put a pinhole on your eye, find a target you cannot > see clear (even it is monitor screen) and see what can happen? > Pinhole glasses cannot work on a very near-sight eye, however, if the hole > size is proper (to allow enough light come while still able to limit the > light through the pupil), you can see a sharper image. I know this. However, you argued that this causes the overuse of one part of the retina, which is false - as the retina can't be overused in that manner. > Ian said that the edge of the pupil can be aberrant -- do you think that the > random edge of a piece of paper is better than our body which is God's > masterpiece? Yes, it can be. The eye is evolved to be used in one way - to provide good vision for hunter/gatherer tasks. As light levels decrease, the iris opens up, and exposes more and more of the cornea, to allow better vision in low light conditions. However, in many peoples eyes, the surface of the cornea is not very accurate over the full pupil diameter, and this will cause blurring that cannot be focused out by the lens in the eye. In most of these, if you select only a 2mm diameter portion of the cornea (as the iris will in bright light) then that portion of the lens is actually better - apart from light gathering ability. Hehe, in this sense our conclusions are the same -- your point is that the optical imaging quality for the central part of the lens is better, which is exactly what I mean. In this way, the field angle is limited; however because a better lens is used, we can see more sharp. Another issue I want to address is the cell size -- it is really smaller than the rest part of retina. When we are using skillfully what God gives us (by applying a small hole to simulate the shrink of the pupil), we get a better image under strong incidence. If you look around you will know that your central part of vision is much much better than the rest, and this is because of both the cell (as a CCD pixel) size and also the way our brain deals with the infomation. Back to the original question, this is unacceptable to an computer user because he will fell better and then he keeps using it this way, however the harmful light will still there and hurts. > In sci.optics Peng Xi <pxi@purdue.edu> wrote: >> I think Ian omit a fact: what if the pinhole glasses has only 1 hole? Can [quoted text clipped - 44 lines] > actually > better - apart from light gathering ability. <Snipola> > Back to the original question, this is unacceptable to an computer > user > because he will fell better and then he keeps using it this way, however > the harmful light will still there and hurts. <Snipola> A computer user....you mean looking at a monitor, right? If so, what 'harmful light' is there? Brian Signaturehttp://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html Sed quis custodiet ipsos Custodes? Do you like censorship and not getting support help? Switch to Supernews! It isn't the light that is harmful. It is the fact that we blink less when using a monitor and don't refocus the eyes regularly. Our eyes weren't designed for staring without blinking which is what we tend to do when working at a monitor. P. Danek > Hehe, in this sense our conclusions are the same -- your point is that the > optical imaging quality for the central part of the lens is better, which is [quoted text clipped - 60 lines] >>actually >>better - apart from light gathering ability. In sci.optics Peng Xi <pxi@purdue.edu> wrote: > Another issue I want to address is the cell size -- it is really > smaller than the rest part of retina. When we are using skillfully what God [quoted text clipped - 3 lines] > is because of both the cell (as a CCD pixel) size and also the way our brain > deals with the infomation. Which is irrelevant. The lens forms an image. Unless you are restricting the field of view, the same cells get exposed to the light, nomatter if you've got a pinhole there or not. This should be fairly obvious - as if it was not true, then the image would shift when you put on the glasses. > I think you'd better wear an coated glass rather than pinhole glasses. I had > a pair of pinhole glass in high school and I know how it works: it just > force your eye to use the most sensitive part -- center of your retina where > the cell is smaller than usual and the paraxial optical quality is better. I've never heard of the word "paraxial" and neither has my dictionary. It's nice that you know they work, however, I don't believe that is correct. There are three ways that I know of that pinhole glasses help vision: 1. They increase the depth of field. If you can't focus near (or far), the pinhole glasses may increase your range to where things are in focus. 2. If you are astigmatic, then the pinhole glasses remove that problem. 3. If you have cataract, then the pinhole may allow you to find an area through the cataract that is clearer. SignatureDan Abel dabel@sonic.net Petaluma, California, USA > I've never heard of the word "paraxial" and neither has my dictionary. You must be kidding: there are 721 entries for the word "paraxial" in Google Search, Sci. Optics. Grandpa. > I've never heard of the word "paraxial" and neither has my dictionary. It's used in optics texts like Fincham & Freeman, for rays that are central or "alongside the axis," as opposed to peripheral rays with large angles of incidence. Eg spherical aberration approaches zero for paraxial rays. -MT > > I've never heard of the word "paraxial" and neither has my dictionary. > [quoted text clipped - 5 lines] > > -MT Paraxial refers to the approximation of the angle of a ray being equal to it's tangent. This is close to reality for small numerical apertures. > > I've never heard of the word "paraxial" and neither has my dictionary. > > It's used in optics texts like Fincham & Freeman, for rays that are central > or "alongside the axis," as opposed to peripheral rays with large angles of > incidence. I took an optics course. It was in 1969, and was a one quarter physics class. SignatureDan Abel dabel@sonic.net Petaluma, California, USA
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