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What Font Color Is Best For Eyes?
Posted by
kdawson
on Tue Apr 08, 2008 09:32 PM
from the blue-definitely dept.
from the blue-definitely dept.
juraj writes "What font color and what background is best for the eyes, when you work for a long time? I have found various contradictory recommendations and I wonder if you know about any medical studies on this topic."
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Great Blazing Colors (Score:5, Funny)
Re:Great Blazing Colors (Score:5, Funny)
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Mustache Bold (Score:5, Funny)
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Re:Mustache Bold (Score:5, Funny)
YEARS!
(Check my user name.)
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Re:Great Blazing Colors (Score:5, Interesting)
Ok, that post was for fun.
For my shells, that I stare at for hours, I use:
green on black
yellow on black
white on black
It's usually green on black. I use yellow on black for special shells (like when I'm using a lot of shells with cssh). Putty defaults to white on black, so when I'm stuck in Windows land, that's it.
Any shells that default to black on white, I switch immediately. It's not so bad in a web browser, but there's something about a shell and typing in it that hurts my eyes. It could be that I'm concentrating that much more on the text on the screen, since it's usually fast data. Like, tail logs on a busy server, or run top with a refresh of 1 or 0. I catch details that other people don't even notice on their machines.
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Re:Great Blazing Colors (Score:5, Insightful)
Any shells that default to black on white, I switch immediately. It's not so bad in a web browser, but there's something about a shell and typing in it that hurts my eyes.
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Re:Great Blazing Colors (Score:5, Informative)
Our eyes can differentiate shades and hues of green better than any other colours -- this is an inherited survival trait from when it was important to see predators and distinguish ripe from almost-ripe. Blue, on the other hand, wasn't as important to survival, so we can't tell too many shades of blue apart, nor very far towards ultraviolet. We perceive indigo (the traditional indigo, not the "purple" that's called indigo these days) as a dark colour, for example, because it's at the edge of what we can see.
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Re:Great Blazing Colors (Score:5, Interesting)
Yeah. That's also why unless you are colorblind, light yellow on a very dark blue will probably be about as readable as it gets because it has both luma contrast (difference in rod response) and chroma contrast (the yellow hits the red and green cones hard with just a little on the blue cones, the blue hits the blue cones and barely registers on the others). Even if you're colorblind, the huge difference in contrast should be sufficient to make it reasonably readable.
The absolute worst, IMHO, is white on medium green... you know... road sign colors. Unreadable until you get right up to the things, by which time you end up cutting off the guy in the next lane to slam your car into the exit lane that should have been marked 200 feet earlier.... :-D
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Re:Great Blazing Colors (Score:5, Insightful)
I still wish someone would start requiring road signs to be sized appropriately for the speed of the roads. Speed limit signs are required to be larger in places where drivers go faster to give them additional distance (time) to be able to recognize the sign. Road signes need to do the same.
Additionally, we should have cross street hanging signs (the big ones hanging from traffic light wires) on every block in cities... Here in my city, it's hit and miss, some streets have them, others don't. if I'm in the left lane, there's little hope I can read a street sign, even when parked at a light. It's simply too far away to read 3" tall letters... especially on green backing.
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Re:Great Blazing Colors (Score:5, Informative)
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Re:Great Blazing Colors (Score:5, Informative)
Our eyes don't work like that -- they don't scan the visible spectrum from low to high, and see blue as the opposite end of red. Instead, we have receptors for certain colours, and base our colour perception on how much each of those get triggered. This is why colour blindness hits red/green or yellow/blue, despite those colours not being adjacent on the spectrum.
Yes, we have different color sensors, but this is beside the GP's point. The green response curve overlaps significantly with red and blue. See the spectral response here [ed.ac.uk]. Red/Blue flashing lights will cause a significant color contrast as they alternately hit one type of cone and then the other. Even though the response to blue is low, it is still an effective color to use because the human eye's response is logarithmic wrt to brightness (i.e. take the graph I linked above and take the log the y dimension). Even that's a simplification when you add rods to the mix, but that's a subject for another post or later research.
Our eyes can differentiate shades and hues of green better than any other colours -- this is an inherited survival trait from when it was important to see predators and distinguish ripe from almost-ripe. Blue, on the other hand, wasn't as important to survival, so we can't tell too many shades of blue apart, nor very far towards ultraviolet.
This is wrong. We can identify more hues of blue than any other color, followed by red, while the intermediate hue discrimination can be quite low. Green sucks because that cone's frequency response is highly correlated with parts of the other two, and thus it forms somewhat of a degenerate basis for describing a hue with the 3 weights. Google "Hue-discrimination curve" for more info.
The evolutionary argument for this has *no* good evidence supporting it, but has become a very vibrant meme (I won't call it a legend, since it is an unproven theory). Green is bright for a variety of potential reasons: (1) It's one of the easier pigments for synthesize biologically, (2) There's a lot of green light coming from the sun, (3) It's a good baseline from which to differentiate other colors (there's a lot of green in our environment), and (4) yeah maybe it could have to do with rotten/ripe fruit. I'd bank on the first two though, especially noting that our hue sensitivity in the green range sucks. Predators are best to detect via motion (primarily rods), and by non-green cones (predators are camouflaged best against rods, i.e. non color vision, i.e. luminance, which overlaps most with green). You can of course believe whatever theory you want, but please don't start speaking about one as being authoritatively true; I know some evolutionary biologists like to extrapolate really far from the evidence, but it always hurts when they are wrong on some theory that gets discounted, since it gives creationists a hammer to bludgeon all of biology and science with. Please don't give them that ammo, and label speculation as speculation until there's real concrete evidence to show. For evolution of these traits, that means sticking mostly to the "what" and "how", and not claiming "why" except in the most general and statistically supportable terms.
We perceive indigo (the traditional indigo, not the "purple" that's called indigo these days) as a dark colour, for example, because it's at the edge of what we can see.
It's not just that its near the edge, it's more complicated with several factors: (1) The blue cones are not that sensitive, (2) there is no additive luminance response due to the other cones frequency response falling off completely at violet, and (3) the rods don't even respond to it very well (last point only really matters for
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Re:Leopard OSX fonts a polychromatic and easy to r (Score:5, Informative)
Steve Gibson has an interesting article on it here:
http://www.grc.com/ct/ctwhat.htm [grc.com]
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Re:Leopard OSX fonts a polychromatic and easy to r (Score:5, Informative)
They use a couple of electromagnetic coils in the rear of the tube to guide an electron beam to the right point on the CRT's surface, but it is not so precise on most models (though maybe some really high end stuff for scientific work) as to be able to exactly hit specific phosphorescent spots.
This is why sub-pixel rendering works on LCDs but not CRTs (which turn on and off [or shade] specific color points digitally), because we know the exact shape and color layout of each pixel.
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Re:Great Blazing Colors (Score:5, Informative)
We use red because red is way out the end of the visible spectrum and red light excites the L cones but not the M cones. If we were to use yellow-green we'd be exciting the M cones too much. The average person has about twice as many M cones than L or S cones, (we're very sensitive to green light) so yellow-green ends up exciting the M cones more than the L cones. By adjusting the amount of red (L cone excitation), green (M cone excitation) and blue (S cone excitation) we can replicate in the eye the cone response any visible colour would generate.
The human vision system is not like a camera - the cone response is only one part of a long and complex chain. Afterimages are somewhat a function of photo-pigment bleaching and later stages of visual processing in the nervous system and brain.
Cone response references:
Stockman, A. & Sharpe, L., "The spectral sensitivities of the middle- and long-wavelength-sensitive cone derived from measurements in observers of known genotype'', Vision Research, Volume 40, Issue 13, Pages 1711-1737, 16 June 2000
http://cvision.ucsd.edu/cones.htm [ucsd.edu]
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Re:Great Blazing Colors (Score:5, Funny)
You, my friend, are way out of line.
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Re:Great Blazing Colors (Score:5, Informative)
http://www.ndt-ed.org/EducationResources/CommunityCollege/PenetrantTest/Introduction/lightresponse.htm [ndt-ed.org]
In terms of raw sensitivity, green produces the most signal at the lowest intensity. I've personally found that is true, and green on black is my usual choice; I've tried them all, yellow is next best, which also fits the curve.
As PP points out, though, the visual system is complex, and the receptor distribution will vary for each person. It's also been found (no reference, sorry) that most people read words as a chunk, not by resolving and assembling the individual letters, so choice of font and kerning probably has more to do with readability than the color of the text.
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Re:Great Blazing Colors (Score:5, Insightful)
The result of this was horrific eyestrain. Yes, some people can handle bright colored text on a black background. Most get eyestrain or worse, migraines. This is especially so if you switch from green-on-black to black-on-white (like a printed page).
Typists and transcriptionists and grad students and pretty much anyone who needed to refer to a printed reference hated it. In the early '80s, color monitors were pretty much crap for text (too fuzzy, not enough resolution) so there was a boom in the production of "amber" monitors. These used monochrome CRTs that phosphoresced a muted yellow-orange. This wasn't quite as jarring to the eyes.
Then someone came up with paper-white monochrome CRT's, and that was pretty much all she wrote for greenscreens.
Geeks keep it alive, because of nostalgia and tradition. It's looks high-tech and cool, because there was a time when it was high-tech and cool - and because there is an association with Unix, and by extension, Linux. What's more Unix than a DEC vt100 terminal hooked up to a PDP-11? Nothing. That's about as close to the metal as you can get without a soldering iron.
But, please, for the sake of your eyes and the eyes of others, don't pretend there is any inherent advantage to green-on-black for the vast majority of users.
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Re:Great Blazing Colors (Score:5, Interesting)
The rest of the eye does as it tries to focus and refocus on a dark-but-not-dark environment, and the iris goes between contracting and expanding because it can't get a read whether it should be letting in more light because the background is too dark or contracting because the letters glow too bright, and the part of the brain running the ocular show will often make its displeasure felt in the form of splitting headaches.
For similar reasons, white text on a black background, while not as bad, isn't exactly good. This is why legal pads are pale yellow, and ledgers are pale green. Contrast is good, but too much contrast hurts.
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Re:Great Blazing Colors (Score:5, Insightful)
Don't be pedantic. Tired doesn't just refer to muscle fatigue and retinas do indeed become less responsive without rest.
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Personally I found that (Score:5, Informative)
It generally boils down to: IMHO most people I've seen using computers are doing it wrong for their eyes.
For starters make sure you use a large enough, and clear enough, font so you don't have to squint. If you absolutely need 80 lines on the screen when editing sources, that's usually your clue that there's something wrong with your programming style (and I suspect for some people the short term memory too.) You shouldn't have methods that run over that many lines, unless they're truly trivial stuff. (Like, say, a long switch statement where each line does no more than delegate to a method of its own. Arguably there are better ways there too, but I don't find it to be the end of the world either.)
IDE's also offer a lot of tools to find the method you need, when you need it, and/or collaps/expand blocks so the don't take up screen estate when you don't need them. There's also stuff like showing you the parameters anyway, so you don't have to have a second window in which you look for the parameters to that method. And really lots of other stuff. Use those instead of cramming the absolute maximum lines of text on the screen.
When I see a couple of co-workers squinting at their 6 point Illegible Roman font in VI and doing greps manually in another illegible tiled window, heh, I'm just itching to tell them to move out of the stone age already. We even discovered this funky thing called the "wheel" in the meantime, ya know?
Clean your monitor regularly, especially if it's a CRT. CRT's have thick glass, and your eyes end up focusing back and forth between the dirt on the front side of it, and the letters on the back side of it. But it's distracting and tiresome on TFTs too. And if you need to squint because you're at the point of "is that a 'm' or a 'rn'? Or is it 'rh' behind that speck?" it's long overdue for a cleaning.
Do turn your contrast up, but turn your brightness down to a comfortable level. The monitor is not supposed to be an AA searchlight. Staring into very bright stuff, especially in a dark room, _is_ tiresome. Here especially the TFT's are the biggest offenders. The manufacturers got stuck on bragging about the brightness of their monitors, as if that's something good, and pre-set them to insanely bright levels. Turn that down to where you can live with the white for hours.
And it will be even more important when you have to focus on stuff that's the other way around: white on black. (Some websites love that scheme, for example.) On an ultra-bright monitors that will mean focusing on a mostly black screen, so your pupils are wide open, but some pieces of retina are getting to see some really bright letters. It's a recipe for a headache.
As a side-note, I'm genuinely surprised at how many people do the exact opposite. I've seen too many monitors which are turned to abysmal contrast, and as bright as halogen headlights. I mean, WTF? Some things are barely legible in that configuration.
Ok, so maybe it's good for PC games, where the average dev seems to think that every fucking thing must happen in nearly complete darkness. 'Cause, you know, we have 32 bit colours so we can display all the gamut of "black", "really dark", "dark grey", "room with a broken lightbulb" and "grey stone on a moonless night". But the brightness settings where you see in near dark in games, suck for work or even reading in a browser. If you use the same monitor for games, consider turning up the brightness or gamma up in those, instead of turning the monitor's brightness all the way to the right.
If you're stuck with a CRT, make sure it's a good one and properly tuned. Staring into an unfocused image, especially with small unfocused fonts, is a recipe for a headache.
Again, for CRT users, just because everything idiotically defaults to 60 Hz, is no
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Re:Great Blazing Colors (Score:5, Insightful)
Because the screen directly emits light, it is typically more tiring to your eyes. That's why people often prefer light text on dark background for a screen. I generally choose "old school" green or amber on black.
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Re:Great Blazing Colors (Score:5, Interesting)
http://slinky.imukuppi.org/zenburn/ [imukuppi.org]
http://en.wikipedia.org/wiki/Zenburn [wikipedia.org]
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Eye-friendly color combination (Score:5, Funny)
White on white (Score:5, Funny)
I am and because of that (Score:5, Funny)
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Re:But that's still not as funny as... (Score:5, Funny)
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Colour? (Score:5, Insightful)
When you work with computers for long periods of time, the colour of the font is nothing compared with taking regular breaks. Look out the window. Go for a walk. Make some tea. Bump up the font size. Get a bigger monitor and put it further away.
You are focusing on a tiny, tiny, tiny piece of the problem. There are almost certainly a ton of ways in which you could reduce eyestrain by gigantic amounts in comparison without bothering with something as trivial as font colour.
You gotta explain for us Americans... (Score:5, Funny)
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Re:Refresh Rate (Score:5, Interesting)
For some of us with sensitive vision, looking at a 60Hz screen is like reading text written on a strobe light. Even if it doesn't subjectively bother you, it does cause increased eye strain. Apparently even OSHA cautions against 60Hz.
A good document on this issue ( show it to your librarian, IT pro, or whoever has locked you out of the control panel) is available here: http://www.nhpa.org/docs/ComputerMonitorFlicker.doc [nhpa.org]
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Re:mod parent up (Score:5, Funny)
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Easiest (Score:5, Funny)
Re:Easiest (Score:5, Funny)
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Not color (Score:5, Interesting)
Why, Pink of course (Score:5, Interesting)
Bright BLUE on vibrant RED ... (Score:5, Funny)
a serious response... (Score:5, Interesting)
When I was in uni, I used to buy special black paper "visual arts diaries" and write my class notes using a gold, silver, bronze, or plain white ink pen. This had the effect of making my pretty poor handwriting easier to read for most people, and also reducing the effects of my dyslexia; I would make less errors like inverting a series of numbers as I wrote them down and the like.
Well at least we're all on the same page (Score:4, Interesting)
...because none of us have RTFA - as there isn't one.
Err, that's nice. Where's the links?
Answer: Whatever makes you feel the best (Score:5, Interesting)
I always wondered in medical school what causes eyestrain -- your mom probably told you "don't read in poor light," but since the photons are easily sufficient to give an image on your retina, this didn't make sense to me.
It turns out that your eye muscles have a difficult time obtaining a rapid and precise focus with poor light, which gives less contrasts on the edges that are detected for sharp focus. In low light conditions, the eye muscles are rapidly focusing back and forth, and these micro-contractions can fatigue them similar to the other large muscles of your body. As an analogy, imagine walking on level ground versus on a balance beam. You are constantly contracting different adjustment muscles to walk on a balance beam, using more energy and promoting fatigue.
So, in answer to your question, you would want a high-contrast color scheme to make it easy for your eyes to focus on the letters. "Duh," I hear you say.
Next, I would recommend minimizing the difference in brightness between your monitor and the outside environment and its background. That is, in a dark office have a dark monitor, and in a bright office, a bright one. Why? Well, same reason -- your eye muscles have to dilate your pupil every time you look away from a bright monitor to a dark monitor. More contractions / adjustments -> more fatigue. Not only that, but the high brightness contrast will give ineffective normalization of light across the eye receptors and could cause headache.
Regarding your study question -- difficult to fund, and difficult to accomplish. I guess you would have to divide several hundred office workers, and try to have them work the same hours under same conditions with different fonts, and then ask a subjective question regarding symptoms. It could be done, but I am not sure of any well-performed efforts that have addressed this question.
In summary, I would just choose contrasting colors that you like or find subjectively pleasing, and then keep the brightness on your monitor appropriate for ambient lighting. Also, don't forget to focus on the numerous other ergonomic factors on your workstation. I see a *lot* of people with bad backs from the workplace, but there are a lot of 80 year old secretaries that are not blind.
Cue the contempt for expertise from the anti-intellectual crowd now.
Re:Answer: Whatever makes you feel the best (Score:4, Funny)
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You are on the right track but there is more (Score:5, Interesting)
You are on the right track but there is more. Yes, higher contrast is better than lower contrast. But how this works with color is complicated.
One big issue is that the eye is not perfect optically. It cannot focus all colors at the same focal plane. Just how well it does varies by individual and the optical conditions of their eyes, and the quality of corrective lenses (which usually make it worse with respect to the ability to simultaneously focus all colors).
An important factor to consider here is which color or colors the difference is at the edge being focused on. For example in the "hot dog" pattern that has been mentioned in a reply here, the difference is actually in green. If the red level of the yellow part is exactly the same as the level of the pure red part, then all the difference is in green and this is an issue of green contrast. Yellow on red like this is essentially the same as green on black ... except that the extra red light with yellow on red causes the iris to close down more than the darker green on black would.
I find blue to be the worst to focus with. That may be because my sources of blue light are not sufficiently narrow band in the spectrum. Being spread out over the spectrum, it basically comes in fuzzy. Blue is also lower in contrast.
Green (be it green on black or yellow on red or even cyan on blue) is better.
Red seems to be the best in terms of focusing a sharp defining edge. You get red contrast with red on black or yellow on green or magenta on blue.
Unfortunately, effective contrast goes down when extra light is added in other colors. So you have to find a balance trading off the sharpness of the edge vs. the contrast. I've found a good compromise in orange on dark green (the level of green in the orange is the same value as the green background). Think of the orange in a neon sign on the green felt of a pool table. Then when I need to highlight something, I shift over to pink on cyan ... basically add the same level of some blue to both the orange and the dark green.
A related issue is light quality when reading a book or newspaper. Usually we are stuck with black letters on white paper. The consideration is then what type of light. I find that incandescent light, or sunlight, works nearly best for me for long term reading. Fluorescent lighting is worse. Ironically, I find high pressure sodium vapor light is about as good as, and sometimes somewhat better than, incandescent light.
To understand this, look at the spectrum. Incandescent light has a fairly even level through all light wavelengths. This makes those black on white edges a bit fuzzy. But fluorescent light has two narrowband peaks at a red and green wavelength (the blue is broader). This can make the text edge sharper ... twice. The eye ends up with two contrast edges. I believe this increases the eyestrain by causing the focus to be constantly jumping in and out to alternate the focus on the two different edges. It's a very small adjustment, but it is there at least for me. With incandescent light, it just settles in the middle of the fuzzy range and doesn't change much. And this is affected by how much light there is, which dictates how small the iris becomes. Higher light levels with a smaller iris won't change the effect from fluorescent as much as for incandescent, since with fluorescent the two contrast edges are already rather sharp due to the two narrowband spectral peaks. But for incandescent, the high light level helps (up to the point that intensity is too stressful).
This is why I believe we still need to keep some incandescent lighting around for reading and other close/fine work for long periods of time. I get a headache when working on things I need to look at closely when doing so under fluorescent light. The onset is about 25 to 45 minutes. I don't get the headaches under incandescent. And I have verified that the flicker is not the cause. White LEDs
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myspace (Score:5, Funny)
medium contrast; medium saturation (Score:5, Informative)
My terminals all use a light white on dark grey scheme, and my preferred vim color scheme has been ps_color [vim.org] for quite a while. (here's a useful site for visually comparing a ton of color schemes (in iframes) all at once: http://www.cs.cmu.edu/~maverick/VimColorSchemeTest/ [cmu.edu]. )
ColorBrewer and genuine monochrome (Score:5, Interesting)
I loved my 21" Eizo greyscale monitor. As a monochrome monitor, it had no colour gun registration issues and the text was razor sharp. It also supported 1600 x 1200 at a time when most people aspired to own a 1024 x 768 17" CRT. That is, the design and quality of the output device is also important for long term eye friendliness.
Word Perfect 5.1 or xterm (Score:4, Interesting)
Call me old, but I've always preferred Grey lettering on a Navy background ala Word Perfect 5.1. At least when working on documents where graphics and colors are unimportant. I still keep Word configured that way to today. People accustomed to Black on White think I'm weird(er) for using it that way.
Or when I'm using a terminal, I usually setup a Green on Black color scheme, but Amber text would also be nostalgic. Even a shade of Grey on Black for an alternate nostalgia. SunOS was Black on Grey
My question(s) to you, what are you working on? Is it code? In an IDE or xterm? Do you have multi-color themes, like in an IDE? Or graphic design with lots of colors at once, in which a medium grey is usually standard? Working in a brightly lit, fluorescent bulb cubicle, an office with natural light, a basement with incandescent lights, or a dark room lit only by the neon/led/ccd bulbs of your case mods? These variables could effect your decision as much as anything else.
I think the best way for you to figure it out 'scientifically' is to come up with 5-10 combinations, try them each day at work for 1-2 weeks, and record your thoughts in a journal every hour or so. "Is this comfortable to look at? How's my eye strain? Can I reliably read what I'm doing? etc." Then pick your 2 favorites and try them each for a week straight, again making notes. Then decide on one. You can find what works for you over the long hours. I'm certain that my preference is different from yours. Obviously, you'll need to pick colors with higher contrast to each other, as Lime Green text on a Lemon Yellow background would probably be a difficult setting to get much done in.
x fonts/bg I use (Score:4, Interesting)
green on black
black on wheat
white on navy
cyan on black
orange on black
I use white on navy for emacs.
Human perception, cognition, and computers: HCI (Score:5, Informative)
Text - background polarity affects performance irrespective of ambient illumination and colour contrast. [nih.gov]
and
A study of reading time and viewers' preferences for a variety of combinations of character-background chromaticity for small traditional Chinese characters. [nih.gov]
but don't let me do all your clicking for you:
http://scholar.google.com/scholar?hl=en&q=legibility+of+color+combinations+on+screen&spell=1 [google.com]
Re:Black on Green (Score:4, Insightful)
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Re:Blue on Black (Score:4, Insightful)
I just wish it was easier to select a "dark format" desktop and have everything read my local system settings for colors. I tried at one time, but I got so sick of web pages with white images for backgrounds disturbing my dark reading bliss.
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Re:Infocom had it right: white on blue. (Score:5, Funny)
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Re:A little more info please. (Score:5, Informative)
If you are in a dark room, anything with a white background is waaay too bright, and light color on dark is preferrable. In a bright environment, on the other hand, the you see more reflections against a dark background, so you want to make your background bright, and the font color dark.
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