distance b/w eye's n computer screen?

Question

19" LCD Monitor how far should i sit

Answer 1

move your monitor slightly side way...





as long as you still can see what your doing...





whether your a near sighted or farsighted... then you wont have to move backwards to stay away from direct rediation...





heheheheh :)

Answer 2

Atleast 3 Feet. You must adjust yourself at the farthest distance where you have clear visibility. Though LCD is less dangerous than CRT monitor yet u should take care. Another factor is proper light......

Answer 3

Depends on several things.



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vision



Depending on your eyes, you might be able to see things more than adequately a good bit farther back than someone else. Or vice versa. How big the characters (letters and numbers) are on the screen depends on configuration choices in your operating system (under recent Windows this is adjusted under Display settings in the control panel) and in various applications. In general if you choose those settings to use large characters, so you can sit farther away from the screen, you may have to scroll the displayed screen to the left or right or up and down to see the entire screen.



Lighting is also a factor. If there is a light reflecting off the screen so as to interfere with whatever's being displayed, you will probably have to move it, yourself, or the display to see well.



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posture



We have been reading printed text for several hundred years (about 600 in the West) and there is a great deal of experience with it. That experience tells us quite a bit about the best way for humans to cope with it and with spending much time reading it. No one props a book above a table at head height (as many do today with computer displays), and no one (except the very odd avant garde book designers) makes (or reads) books with green type on a black page or similarly exotic arrangements. Black type on a dull white background (ie, rather like good paper) at a sensible physical placement is best, according to that experience.



If you can arrange your display to be tilted about 30 degrees back from the vertical and centered about 45 degrees down from directly straight ahead (ie, with the bottom edge of the display on the table surface), your neck and back will thank you. Imagine comfortably reading an ordinary sized book. Replace the book with the display, and you'll have found a good beginning orientation.



The usual arrangement (head straight ahead like a first year Armed Forces Academy cadet at table) is not good for various parts of the body:back, neck, shoulders, even hips and legs. Remember that you'll probably be spending considerable time in front of that system attempting to work. The quality of your chair and the height of the table will also matter, and will depend on your physical size in part. Short folks don't fit well into chairs that are satisfactory for tall folks. Adjustable ones sometimes help, but... Beware that there is a good bit of firmly presented, and sincerely too, nonsense abroad about what features chairs should have and how they should be used. Even good advice is hedged about with caution, since various physical conditions modify good choices. A call to a local university and its medical school might be of some help 9the physical therag=py people may have some advice or pointers), or perhaps the industrial engineering department. You're looking for informatin about the 'ergonomics' of the workplace. You may even be able to find some information from the workplace safety regulation folk in your local government.



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radiation and emissions from displays



Same thing actually. It's radiation that being emitted.



CRT displays, like traditional TVs, work by generating an electron beam at the back of the picture tube and directing it against the back surface of the screen. That surface is coated with phosphors (ie, stuff which glows when struck by an energetic electron). The really tricky bit is controlling

that electron beam (turning it on and off, and moving it around with great precision, ...) so that the glowing dots it creates make up the images we can watch with enjoyment. Though the Teletubbies entirely surpass my understanding.



So when you're sitting in front of a CRT display, there are electrons heading straight for you, intercepted only by the glass and the phosphors. These are, in normal operation, sufficiently low energy that no ionizing radiation is generated. Some failure modes in ordinary CRTs (and TVs) can sometimes cause higher voltage electrons and they can emit low levels of low energy X-rays. And very bright (often large) displays have higher voltage beams to begin with, so they needn't be as maladjusted before emitting such X-rays. This, and some concern about eyestrain and eye development, is the reason for the common, and well taken, advice that no one should watch a TV from close to the screen. Anyway, the ionizing radiation is the biologically active sort (X-rays, short wavelength ultraviolet, etc) and should be avoided. Computer displays are generally on the low energy and low brightness end of the brightness scale for CRTs.



But these displays, like all displays, emit a considerable amount of radiation -- visible light, some heat, and so on. None of it is bright enough to be dangerous to sight, as the ordinary radiation from the sun is, and so is highly unlikely to cause damage.



LCD displays are rather different. They generate no light nor radiation of any kind, but merely filter light coming from sources behind them. In the case of LCD displays, the source is several cold flourescent light bulbs behind the actual acreen. They emit, just as do regular flourescent light bulbs, mostly visible light. After being filtered through the LCD screen (aloowed past or not at each of lots of very small pixels) that's what you see.



All that said, there IS a sort of emmission from CRT screens which almost always causes some kinds of trouble. All those electrons banging into the back of the glass screen add up to a lowlevel, more of less persistent, negative charge on taht side of the glass. Any negatively charged surface will attract positive charges, and many of these will be attached to small dust particles in the air. Those particles will be attracted to the screen surface, which accounts for the eternal dust on the surface of CRT screens. Clean them gently...



That's the real problem, one not shared with LCD screens which don't have electron beams at all. The almost always trivial consequence is that, if postive charges are being attracted to the screen surface, there will be eventually enough positive charge to cause other positive charges to be repelled, and negative charges to be attracted. So, if you are inches from a CRT screen, there will be very low speed positively charged stuff streaming away from the screen onto you. If you react to them (eg, positively charged cat dander for those sensitive to cats), you'll come to regard the CRT as a source of itch and irritation. Not the CRT's fault, of course, but all those particles floating around in the air. Get an electrostatic filter, get a HEPA fan filter, put the cat in antoher room, or vacuum with a good vacuum cleaner. Or get an LCD display.



Hope this helps...

Answer 4

exactly 2.5 feet

Answer 5

While most people using Everything2 sit at a computer to do so, research has shown that many of these people do not sit correctly, or work under suboptimal conditions. The result is not unusual: Carpal Tunnel Syndrome, back and neck pains, eyestrain, and headaches. The strange thing is that many people simply accept these (often minor) aches and pains as a result of using a computer, when in fact these annoyances are easily avoidable with a little planning and effort. The following sections cover various different aspects of sitting at and using your computer, and should, if followed correctly, make your computer experience far more pleasant.



Placement of your computer in the room



One of the major cause of eyestrain when using a computer can be attributed to glare. Therefore, your computer screen should not be directly next to or directly opposite a bright light or window. Reflected glare can make it difficult to make out what is seen on the screen, and having your eyes constantly adjusting to a bright light directly next to your screen can lead to tension headaches. If necessary, move the light source to another part of the room or invest in heavy curtains. Anti-glare screens can help, but tend to make the text on the screen fuzzy and difficult to read. If you are in an office situation, then check with your IT department before moving equipment - moving equipment without permission can constitute a breach of your IT policy. If necessary, speak with your manager, as new curtains are often a small price to pay for increased productivity and decreased medical fees.



Placement of your computer on your desk



Your computer (particularly your monitor, keyboard and mouse) should be at a comfortable height for you when you sit down. This means that your elbows are just above the desk when you sit down at it, and your monitor should be raised if necessary so that you look at it straight on, without having to look down or up. Your feet should be able to rest comfortably on the floor. Your computer should be square with the edge of your desk, so that you do not have to lean in any direction to use it. Your keyboard should not be obstructed with bits of paper, and you should use a mousepad to keep your mouse moving smoothly. The use of cable ties to tidy up the cables running around and behind your desk can make a big difference to the neatness of your work area. If cables are a big problem, wireless keyboards and mice are relatively inexpensive, and newer models use up very little battery power, meaning that a single set of batteries can last for months at a time. When buying a keyboard, try and get one with a wrist rest, as these do cut down on wrist problems.



Making your screen easier to work with



A fuzzy, poorly looked after monitor is not pleasant to work with, and once again, can cause eyestrain. However, there are a number of ways to clean up your monitor, and make it easier to work with. The first thing to remember that while monitors get fuzzy or blurry with old age, this can be fixed by most TV repairmen - in many cases, monitors have a small dial inside them that can be adjusted for sharpness and clarity. While this will not help all monitors, it will make a big difference to those it can. Your monitors refresh rate can also affect you over a period of time - this can be changed under Windows by:



Clicking on Start.

Clicking On Control Panel (or Settings and then Control Panel, depending on your version of Windows).

Double Clicking on Display.

Clicking on Settings, at the top right.

Clicking on Advanced, at the bottom.

Clicking on Monitor, at the top.

Selecting a refresh rate higher than 60 Hertz. Try and select the next highest refresh rate, as some very old monitors can be damaged by trying to display a refresh rate that is too high.

Clicking on OK at the bottom.

Your computer will attempt to display the selected refresh rate. If your screen goes dark, wait for a few seconds, and your computer will revert to the original setting. If you can see the screen clearly, then click on OK.

Click on OK, and then OK again.

Close the Control Panel.

Under Mac OSX, you can:

Click on System Preferences in the dock.

Click on Displays.

Adjust the refresh rate.

Bear in mind that some monitors (and video cards) cannot work at anything higher than 60 Hertz. It is for this reason, among others, that I recommend to anyone buying a new computer that they purchase the best monitor they can afford, as a good quality monitor will pay for itself over and over again. The next step is to decrease your brightness - many people turn the brightness and contrast to maximum on their monitor, which makes the screen easier to see, but also makes the monitor too bright, leading to eyestrain. If the computer is in a reasonably dark room, and is not reflecting any glare, you will find that you can turn the brightness down a long way and still find any text very visible and easy to read. In general, your contrast should be set to maximum, but if you have turned your brightness all the way down, you can decrease your contrast a little bit as well. The end result should initially be a little difficult to make out, but you will find that your eyes quickly adjust, and your monitor will be much easier to work with for extended periods of time. Furthermore, when working on your computer, try and look away from your monitor every fifteen minutes, as research has shown that this helps prevent short-sightedness. One last note - although monitors are shielded, it is not advisable to leave them next to magnetic sources for extended periods of time, as these can cause your monitor to display strange colours in different parts of the screen. Please note that while computer speakers are magnetic, they are usually shielded as well, and do not constitute a major risk. Subwoofers are the exception to this. If this has happened to your monitor, speak to a television repairman or your IT technician.

General maintenance



A clean, uncluttered computer is far more pleasant to use. Try and keep your monitor and keyboard clear of Post-Its, bits of paper, cards and so forth. The same applies for your desktop - if you remove unneeded icons from your desktop, and use a well thought-out directory structure for your documents and files, you will be able to find things much easier, and be more efficient as a result. By using a damp cloth and a little soap or detergent, you can clean your monitor, mouse and keyboard, which can improve the general cleanliness of your office or workspace. A noisy computer can also be an irritation - speak to your computer technician, as squeaky bearings in fans can be oiled, and dust can be cleaned out from inside your computer, making it much quieter. If your mouse is jerky and difficult to move around the screen, then you can clean it by turning it over, removing the cover and mouseball, and gently cleaning the dust and grime from the rollers inside with an earbud or small piece of cloth. Better yet, you could buy an optical mouse, which has no moving parts, and works on any surface that is not reflective. If your computer stops responding for seconds at a time, or is much slower than usual, especially when connected to the internet, you could have spyware or adware installed on it. Details on this can be found at Malware: A Layman's Guide. If your keyboard sticks, or does not work properly, ask your IT department to replace it or buy one yourself - keyboards are cheap, and a good quality keyboard will, like a good quality monitor, pay for itself over and over.