Return-Path: Received: from ius4.ius.cs.cmu.edu by K.GP.CS.CMU.EDU id aa24104; 4 Feb 93 11:26:39 EST Date: Thu, 4 Feb 1993 11:25-EST From: David.Simon@IUS4.IUS.CS.CMU.EDU To: bovik@CS.CMU.EDU Subject: Eyestrain Message-Id: <728843135/das@IUS4.IUS.CS.CMU.EDU> I received quite a few responses to my recent query about computers and eyestrain. Thanks to Derek Beatty, Amy Zaremski, John Hagerman, Gary Shaffer, Hank Walker, John Mount, Dirk Langer, Steve Cochran, Nigel Goddard, Tom Sheffler, Jeff Friedl, Lonnie Chrisman and Sarah Gibson for their suggestions. The following is summary of factors which could potentially contribute to eyestrain (as suggested by the respondents), and recommendations for minimizing the effect of these factors. The full text of the responses is included below (LONG). eye dryness: make a concious effort to blink use eye drops and other eye lubricants hot washcloth treatment glare: adjust screen and ambient light positions to minimize glare use anti-glare covers use anti-glare and anti-UV coatings on eyeglass lenses don't wear brightly colored clothing which can reflect off of the screen font: select large, easily readable fonts (9x15bold, "-*-courier-medium-r-normal--20-*") color: select dark background colors!!! (black) select foreground colors to maximize contrast (white, cyan, green, orange) select screen colors that are compatible with the surrounding environment muscle fatigue: periodically refocus eyes on distant objects periodically take breaks from the computer monitor placement: choose low-intensity backdrops (e.g. grey walls) position monitor at eye-level other factors: minimize 60 Hz flicker of the monitor minimize fluorescent light reflections One suggestion which I found quite useful for selecting suitable colors came from Jeff Friedl: (full text below). > I use a few tests when choosing a color scheme for X. > The eye is very good at attempting to overcome adversity. Therefore, > I set up the colors to test, close my eyes for a few moments, then > open and look. If there is any hint of discomfort in the first half > second or second, I know it's bad. Then I take a good look (stare) > for a longer time... 10 ~ 15 seconds. If it starts to "swim" (effects > of eyes open w/o blinking asside), I know that's bad too... I made a few small changes to my own X environment, and quite amazingly, my eyestrain is practically gone (almost immediate results!). The most significant change was setting all of my window backgrounds to black (several of them were formerly white). As several people pointed out, using bright backgrounds is one of the worst possible things you can do for your eyes. After experimenting with a number of different foreground colors (using Jeff's test above), I decided on orange (good contrast with minimum intensity). I also changed my xterm and gemacs fonts to 9x15bold. Small changes, big payoff!!! I did not receive any pointers to formal studies on computer induced eyestrain, although I'm sure that there must be some out there. If I find any, I'll post a follow-up. Thanks again to all who shared their wisdom. David P.S. I'll send a copy of this post to Harry Q. for posterity. **************************************************************************** 02-Feb-93 21:00 David Simon Eyestrain and Computers? From: David Simon I'd like to learn more about factors which contribute to eyestrain when working with computers. Lately, my eyes have been getting sore towards the end of the day. Before I run to a doctor to have my eyes checked, I'd like to make some changes to my visual computing environment to see if that helps. Unfortunately, I'm not sure what kind of changes to make. I imagine that factors such as font size, background and foreground color, screen intensity, glare from ambient light sources, etc. all contribute in one way or another to eyestrain. Before I start making changes, however, I'd like to learn a bit more about the topic. I would appreciate pointers to sources of relevant information, and recommendations on environment configurations which you have found to be good at minimizing eyestrain (ie: particular X colormaps, glare reducing devices, etc). Please email responses to me, and I will post a summary to general if there is sufficient interest/response. David **************************************************************************** Date: Wed, 3 Feb 1993 08:19:24 -0500 (EST) From: Derek Beatty Sender: Derek Beatty Subject: Re: Eyestrain and Computers? To: David Simon Content-Type: TEXT/PLAIN; charset=US-ASCII I've made far too many visits to far too many ophthalmologists since I started grad school. In my case, the principal problem is that my eyes get too dry. This is caused by a combination of things, including the (lack of) humidity. Here are a few things: Try to reduce glare, first by adjusting screen position and ambient light. I think the general rule is that if you can see a reflection from the surface of the screen, it's going to bother you. Use as legible a font as you can stand. I think I use schumacher-clean or something like that; I've also liked some of the courier fonts. In addition to personal preferences, pay attention to the physics of optics when selecting colors. Different light frequencies refract differently. So red appears to be "in front of" blue, for example. What was most important for me was to make a conscious effort to blink. If you're using a program that blinks the cursor, use that as a reminder to blink. I also have found some of the over-the-counter lubricant eye drops to be useful. The trick if you have dry eyes is to use the drops before the discomfort begins---afterward is too late. There are many brands, and you might want to buy one of each, and see which seems best for you. If you wear glasses, keep them very clean, and consider anti-glare lenses if you don't have them already. Good luck. Maybe you'd want to forward your collected results to bovik as well as the bboard. -- Derek_Beatty@cmu.edu ABD Comp Sci, CMU, 5000 Forbes, Pgh, PA 15213 USA ***************************************************************************** Date: Wed, 3 Feb 1993 10:13:40 -0500 (EST) From: Derek Beatty Subject: more on eyestrain To: das+@ius4.ius.cs.cmu.edu Content-Type: TEXT/PLAIN; charset=US-ASCII I forgot to mention that breaks are important too---every so often, focus on something distant for a few seconds. If you have a window, look out of it; if not, peek out the door and down the hall. Every 20 minutes is probably a reasonable interval. ***************************************************************************** From: Amy Moormann Zaremski Date: Wed, 3 Feb 93 09:20:59 EST To: David Simon Subject: Eyestrain and Computers? I had so many problems with my eyes when I moved here and started grad school that I had to give up contacts. Here are a few things I've picked up along the way from random visits to eye doctors and conversations with other people who have similar problems: - do all you can to reduce the glare. I had a special anti-glare cover that went over my screen for a while when I had a super-glare RT. My new machine(Pmax) has an anti-glare screen, which seems to work OK. - every 20-30 minutes, look away from the screen and focus on something far away to give the eye muscles that do close-up work a rest. - don't wear white or nearly white clothing (or at least not tops) -- you can get glare from your clothes reflecting off the screen! - use fairly big fonts. I use 9x15 for my xterms and "-*-courier-medium-r-normal--20-*" for my gnu-emacs. - do get your eyes examined; if you're squinting, it makes things worse. - if you do wear glasses, consider getting two things on the lenses: -- an anti-glare coating. They developed these for cosmetic reasons (your lenses aren't as noticeable when people look at you), but they also help reduce glare from light coming in from behind your head and bouncing off the inside of the lens and into your eyes. No strong evidence on this one; only a theory from my most recent optometrist (I've seen 4 ophthalmologists/ optometrists now in 5 years). -- a tint. What color is dependent on your monitor, I think. Grey tint for black&white, something else for green... Please do post a summary; I'd be interested in any specific references people give, or any other useful tips you receive. -Amy Moormann Zaremski amy@cs.cmu.edu ***************************************************************************** Date: Wed, 3 Feb 93 09:33:46 EST From: John Hagerman To: das+@ius4.ius.cs.cmu.edu (David Simon) Subject: Eyestrain and Computers? I use a white foreground on a black background, courier14 for most applications (on a 14" screen) and courier18 for reading news (so I can sit back and eat lunch at the same time). I've found that it is better to specify colors per application (ie, rather than specifying *Foreground and *Background) because some applications don't follow resource conventions very well. Do you wear glasses? When I went to Dr. Fred a few years ago, he suggested I get contacts to reduce eye strain. The claim is that since glasses properly correct only when you look through the center of the lens, your eyes work harder when scaning over the screen. It sounds plausible, and I got contacts, but there are many things to consider (not the least of which is cost). - John ***************************************************************************** Date: Wed, 3 Feb 93 09:57:57 EST From: Gary Shaffer To: das@RI.CMU.EDU Subject: eyestrain Yunno, in the last couple of years, it seemed like my eyestrain was increasing, so finally, this fall, I went running to an opthalmologist. (I also had *never* had a thorough eye exam in my life, so I thought it would be a good idea.) It turned out that I need a very slight correction, so slight that the doctor said it wasn't necessary to get glasses. As for my strained, constantly bloodshot eyes, he said as I was getting older, my eyes were not generating as much lubricant -- they were just a little dry. He suggested hot washcloth treatment every night (yeah, right, what a pain in the butt). Or if it's really bothering me, he gave me a prescription for some sort of eyedrops I could get. I chose to just deal -- I was just glad that after a thorough exam, he said there was nothing wrong with my eyes. - Gary ***************************************************************************** Date: Wed, 3 Feb 93 10:45:27 EST From: Hank Walker To: das+@ius4.ius.cs.cmu.edu (David Simon) Reply-To: dmw@ece.cmu.edu Subject: Re: Eyestrain and Computers? I can't remember where I saw the article, but one of the major contributors to eye strain is repeated focus changes, due to glare, looking at the screen and then things at a different distance or size, etc. Obvious solutions: if you are looking back and forth between screen and paper, keep them at the same distance; use fonts and colors with sufficient contrast and size that they can be easily read; use screen colors that are compatible with the surrounding environment [1], e.g. wheat background. [1] This is one reason computers have a neutral, sort of cream color, it smooths the change between screen and nonscreen. The black of Next is a definite no-no. ************************************************************************* To: David Simon Subject: Re: Eyestrain and Computers? Date: Wed, 3 Feb 93 11:34:38 EST From: jmount@TINMAN.OZ.CS.CMU.EDU Sender: jmount@TINMAN.OZ.CS.CMU.EDU I went to the eye doctor for eyestrain and it turned out to be problems with my tear-ducts (not getting enough fuild on the eye). The symptoms were red irritated eyes that felt hard to focus- the cure was synthetic tears (NOT bleaching eyedrops). John -- --- It is kind of strange being in CS theory, given computers really do exist. John Mount: jmount+@cs.cmu.edu (412)268-6247 School of Computer Science, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh PA 15213-3891 ************************************************************************* To: das+@IUS4.IUS.CS.CMU.EDU Subject: Eyestrain Date: Wed, 03 Feb 93 11:40:58 EST From: Dirk_Langer@IUS5.IUS.CS.CMU.EDU Hi David, I found that some of the eyestrain is due to the flicker from the monitor, i.e. the 60 Hz scan rate, even though you may not notice it consciencely ( <- sorry that word may be spelt wrong). So what I do to minimize the effect is to use white characters on black background in windows, use a large and bold font (9x15bold), and use a dark coloured background as my main background. Of course black would also be best here. Hope that info helps, Dirk **************************************************************************** To: das+@IUS4.IUS.CS.CMU.EDU Subject: Re: Eyestrain and Computers? Cc: Bcc: Date: Wed, 3 Feb 93 11:54:08 EST From: sdc@ESPRESSO.MAPS.CS.CMU.EDU Sender: sdc@ESPRESSO.MAPS.CS.CMU.EDU In article you write: > >I'd like to learn more about factors which contribute to eyestrain when >working with computers. Lately, my eyes have been getting sore towards the >end of the day. My doctor told me that Human eyes were not designed to stare at objects a foot away for long times. He suggested that I look across the room for awhile every 15 minutes or so. (He also gave me a prescription for glasses to wear for staring at a terminal that I never used.) This suggestion cured my problem. Steve -- Steven Douglas Cochran, Digital Mapping Laboratory Carnegie Mellon University, Pittsburgh, PA 15213 Email: Steven_Cochran@CS.CMU.EDU (128.2.222.173) Phone: (Office) 412-268-5654 (Home) 412-422-4350 **************************************************************************** To: das+@IUS4.IUS.CS.CMU.EDU Subject: Re: Eyestrain and Computers? Cc: Bcc: Date: Wed, 3 Feb 93 11:57:35 EST From: goddard@B.GP.CS.CMU.EDU Sender: goddard@B.GP.CS.CMU.EDU David, I heard that research had shown that orange on black or green on black are the easiest on the eyes. Consequently I made my X environment green on black. Not sure if it made a difference. Now I use white on black since my monitor is gray-scale. If you use a white background basically you are looking straight into a lamp all day. Other folk-wisdom: Have the monitor against a low-intensity background such as a wall. Ideally you should be able to look away from the monitor and focus on something distant, e.g. out the window, and you should do this periodically. People tend not to blink as much when using a computer so if you can make yourself blink more often it might help. Monitor should be at eye-level, i.e., center of monitor. Reflected light is really bad. I would be very interested in references to hard research in this area. Nigel **************************************************************************** From: Thomas Sheffler Date: Wed, 3 Feb 93 12:14:59 EST To: David Simon Subject: Eyestrain and Computers? A few years ago, I was developing severe eyestrain during the course of the day. It became so bad, that I every hour I had to stop because my head hurt (it's a good idea to take a break from your monitor anyway). I had my monitor checked and refocused, and that didn't help. Turns out I had stupid screen colors. I had made my Xterms look kinda like 'paperwhite' backgrounds w/ BLACK text. I went to BLACK backgrounds, w/ CYAN (or WHITE) text foreground. CYAN is close to what IBM put on their old terminals. Apparently, the eye is most sensitive to this color range. Within two days of making this change, my eyes were back to normal. -tom **************************************************************************** To: David Simon Reply-To: jfriedl@cs.cmu.edu Subject: Re: Eyestrain and Computers? Date: Wed, 3 Feb 93 12:53:17 EST From: jfriedl@TUBBY.MACH.CS.CMU.EDU Sender: jfriedl@TUBBY.MACH.CS.CMU.EDU In article , you write: |> Lately, my eyes have been getting sore towards the |> end of the day. Hi Dave. Some random thoughts.... If you have contacts (I don't remember, but think you might not), changes in airflow which are otherwise virtually undetectable can have a major inpact on your eyes (dryness, etc.). But if you wear contacts, you're likely more than familliar with the different kind of discomfort that arise due to the contacts (rather than eyestrain). I use a few tests when choosing a color scheme for X. The eye is very good at attempting to overcome adversity. Therefore, I set up the colors to test, close my eyes for a few moments, then open and look. If there is any hint of discomfort in the first half second or second, I know it's bad. Then I take a good look (stare) for a longer time... 10 ~ 15 seconds. If it starts to "swim" (effects of eyes open w/o blinking asside), I know that's bad too... I don't know what causes eyestrain, but I would *guess* that it's the effect of your eyes having to overwork. If you're trying to keep a focus of 2.5 feet for hours at at time, and your eyes just can't naturally focus that closely (getting old there, Dave :-), that'll hurt after a while. Perhaps the strain has nothing to do with computers per se, but with the distance your CRT is and the length of time you focus at that distance. Maybe trying different distances.... (??) FYI, here are some color schemes I use. I find them very pleasing to my eyes, but some people just can't handle them. Also, they may appear different on your hardware.... generic background: busy multicolor picture of my teddy bear. generic xterm: -bg black -fg seagreen wild xterm: -bg black -fg cyan [I can't look at this one too long... ouch!] subdued xterm: -bg black -fg darkslategray [maybe too dark for common use] my newsreader colors: -bg darkslategray -fg black [very pleasing to me] special xterm (for window newsreader pops up to reply to news): -bg seagreen -fg black You'll note that most of my xterms are colored letters on a black background. Most people tend to use the X default of a white background with black letters. Ouch. At first it's hard to get away from that if that's what you're used to, but once you get used to the reverse, you never want to go back [it seems so bright]. And when I have the colored letters on a black background, I generally use subued colors (seagreen, darkslategray) rather than wild ones (for this purpose, white would certainly be considered "wild"). Lots of random stuff there.... hope something is helpful. yoroshiku, *jeff* ************************************************************************** Date: Wed, 3 Feb 1993 15:32-EST From: Lonnie.Chrisman@FLOWER.LEARNING.CS.CMU.EDU To: David Simon Subject: Re: Eyestrain and Computers? David, Just my personal experience, but I've had a couple jobs where the same thing happened to me. I'd go home every night with a headache. I had no doubt that it was the environment. The two things that seemed to bother me were: 1. Too much "white" on the screen. 2. Fluorescent lights Now I always use black backgrounds on all windows, etc. Inverted windows (black text on white background) will almost always result in headaches after several straight hours of looking at it, for me at least. That simple change is probably the most important thing. I found it successful. The more pixels "on", the better. The other thing is the lights. I have no idea what it is, but I just know that there is something that has to do with the way flourescent lights interact with a screen that can give me a headache. The same computer in incandescent lighting doesn't have the same effect. Sometimes fluorescent lighting doesn't bother me, sometimes it is unbearable. I don't know what the parameter is that makes the difference. I'd like to find out. Lonnie **************************************************************************** Date: Thu, 4 Feb 93 09:28:36 EST From: Sarah.F.Gibson@IUS5.IUS.CS.CMU.EDU To: das@IUS4.IUS.CS.CMU.EDU Subject: more about eyestrain Cc: sgibsn@IUS5.IUS.CS.CMU.EDU, sgibson@IUS5.IUS.CS.CMU.EDU David, here are my parent's experiences with eyestrain on the computer: ---------------------------- I have done two things to counteract eyestrain. One was to get special glasses with built-in UV screening to wear on the computer. They are set for the distance I want to be from the computer. I really notice a difference when I forget to put them on. The second thing was to buy an anti-glare screen from Inmac. It was quite expensive, but I think worth it. Actually I bought a cheaper one in CA (only about $36 or so) for the little computer at home, and it seems to work just as well. But I don't spend 10 hours a day in front of the computer - if I spend that long, I still notice it. But both those things helped a lot. Hi again. I told Dad about your friend David's problem and he said to tell him he has found a surefire way of avoiding eyestrain from spending two much time on a computer. 1) You buy a piano and start taking piano lessons. Practice regularly. 2) Buy a couple of old MGs that need a lot of work. Have a good day. Love, Mom. ---------------------------- talk to you soon, Sarah