• Abstract

  • Anti-aliased fonts can damage eyesight - writeup

I am currently running Debian 8.2. Trying if I get used to the (small) eyestrain I always have under Linux.
I use proprietary NVIDIA drivers with dithering disabled. Well I hope it is really disabled.
So far I feel no difference between font antialiasing off and on. But in VESA text mode (no KMS), there is no eye strain at all. Disabling hardware acceleration in xorg.conf (Accel false and NoAccel true) did not help.
There is no Linux eyestrain from within Windows (10), be it a virtual machine or a VNC remote connection. Which makes me think the problem is something only a physically connected monitor can show. A driver problem, something open and closed source drivers have in common - or an Xorg problem.

If you have Linux eyestrain, too, let's try to isolate the problem. All major desktop environments should be able to disable font antialiasing (sometimes called "smoothing").

I noticed that Linux uses different video modes than Windows. You can recognize this when you use a VGA connection, factory reset the monitor and then first run Windows, then Linux (same resolution and refresh rate). The monitor will have to auto-adjust, telling me that the Linux mode is a new mode that has not been saved before, and that something is different even though it says 1080p@60Hz in both examples.

3 years later

JTL

Looks it affects only non-retina and external displays. Also mainly white text on black background. I have MPB Retina + Air and CCFL (Dell ST2410b) and LED IPS (ThinkVision P27h-10) monitors...which both are bad with both MACs but good with my recent Chromebook discovery. I'm headed home from work, and upgrading my Air to Mojave first thing I get home.

...Looks I've missed all this "font antialiasing" software issue, kinda just discovered it today (yes I'm
late couple of years) and I think this is part of my issue (text feel very smooth, sometimes even bold) where the chrome does not have this, the font feels thin, I can see the square pixel and even white/grey pixels in the font which I turned to love last 2 weeks!!!!

This article explains it great
http://www.lighterra.com/articles/macosxtextaabug/

I have to test disabling it in chrome://flags too, which just says Default, but I have no clue if that means enabled or disabled (my guess this is disabled in chromebook but enabled in mac)

Will test if I feel difference on the Dasung HD too (which I'll be returning next week)

  • JTL replied to this.

      daniel_mate I haven't used Chrome in quite a while so I can't help you there.

      If I remember correctly Chrome on OS X did "inherent" the OS font rendering settings but I could be wrong. I remember under Windows with Chrome it had it's own antialiasing settings that needed to be disabled.

          JTL

          Updated the Air to Mojave...the weird part is by default anti smoothing was still enabled! I disabled it and can definitely say it's easier on my eyes and I get the chromeebook font feel!
          However it comes with slight drawback, on dark backgrounds the white font seem little blur, the opposite also feel slight blur but not as much. This "blurness" is not as bad on my external CCFL as it is on the Air display but either way I find it much more usable this way than with smoothing enabled! The chromebook does not have this blurness at all, neither the external display when connected to it.

          Other good thing with Mojave is it comes with Dark theme option (asked on first boot if want to pick it). Tho both options are under Settings - General.

          ...will update the Retina one on Monday (must bug IT at work, I don't have permissions) and will see how this affects it (since other article said Retina won't get blurred)

            Definitively disabling anti-smoothing makes my Air more usable. I can't tell yet if it fully eliminates my problems tho!! I do not see the fonts blurry with the smoothing on (usually complains from the rest) but somehow my eye can't lock on them and keep seeking.

            On the Retina, this flag does not make any difference, no improvements, which makes me think my eye simply can't handle Retinas high pixel density. However when I plug the external monitor, it becomes usable!!

            Regards the iPhoneX have:
            https://graphicdesign.stackexchange.com/questions/8277/how-does-apples-retina-display-affect-sub-pixel-rendering
            Subpixel rendering is not happening if the display is not in the normal orientation.
            This is the main reason why iOS doesn't have sub-pixel text rendering!! So I guess this goes back to my Retina theory (Super Retina in the case of iPhoneX) and why I cant use it. This screen is way worse for me than any other screen I have looked at (I have this phone mainly for the camera with portrait mode :S)!
            https://www.lifewire.com/what-is-retina-display-2000362

            I'll try to work with the Macs instead the chrome this week, if I don't get the chromebook relief then dithering is next vector of attack. Just I can't test this on the Macs :S

            Damn, looks there are anti aliased shapes too, not just fonts!

            The picture on the right is the only thing so far I have looked at on my chromebook that I can't hold my eyes, it gives me the same eyes flip feeling instantly as when using the MACs (till yesterday when disabled font anti aliasing and used external monitor)
            https://helpx.adobe.com/photoshop/key-concepts/aliasing-anti-aliasing.html

            Ok that picture is too big and blurred too (with fonts I don't feel the blur part)
            This one is smaller, the most right box is too hard to look at for me, instant discomfort.
            https://bjango.com/images/articles/1pxisnotenough/1px-aa.png

            I guess you guys see them blur too, but does your eyes feel like want to flip or maybe cross trying too hard to focus or there is nothing?

            JTL Thanks!!

            On Mac and Chromebook it says Default, so it inherent from the OS
            On Mac default for the OS is Enabled
            On Chromebook have no clue how to check, haven't enabled developer mode yet, but visually I can tell it's Disabled.

            Just for any case this OS setting not to change, I have manually disabled it in chrome
            chrome://flags/#lcd-text-aa

            Can't speak about Win, haven't used for too long. My original issue started 2011/2012, I was on Win 7 back then, I had switched from XP, I can't tell now for how long it was after the switch but I think I used it for at least a month. So I guess or I built this intolerance gradually or I got auto update with "Clear Type" fonts! But it all started on what seemed a regular morning, went to the office, turned on the monitor and I couldn't look at the screen! I had x8 Dell CCFLs, couldn't look at any of them. When went home, I couldn't look at my MBP 2010 too! I can't recall but I think I did not have problems then with my 2G iPhone...

              This is very interesting. I will test it. Do you think in windows 10 of the newer versions this could work too? I remember playing around with cleartype but having no success, maybe it would work if its completely overridden.
              Btw. IRIS software had this option of overriding all system fonts into non-aliased version, have you tried it? Could be a good solution to get rid of this for certain so then testing it is easier.

                martin With regards to Windows 10 I don't know.

                  MS has been moving away from cleartype for a long time now even in 7. If you installed a current version of IE, you lost cleartype. If you installed a version of Office higher than 2010, you lost cleartype.

                  It only works in landscape orientation, and pretty much only on white backgrounds.

                  Fonts were specifically designed to be used with "cleartype" rgb subpixel anti-aliasing (e.g. Calibri, etc.), or no anti-aliasing (Verdana, Georgia, etc.), or greyscale anti-aliasing.

                  Match the fonts to the rendering you prefer, you'll get better display results.

                  It's true about the Verdana/Georgia and a few others. They were done as bitmaps first, and then outlines wrapped around them which is never done anymore. I love Verdana on the screen.

                  martin Will give it a try to Iris tomorrow, haven't used it yet.

                  I think you understood me the reverse way. I cannot handle smooth fonts and shapes and since ~2012 everything I have put my eyes on seems uses this by default!
                  Keywords for this are font rasterization, subpixel rendering, font anti aliasing, subpixel AA, LCD font smoothing (Apple), ClearType (Windows)

                  As soon I turned this off, I could instantly feel more comfort. I would say 90% my issue is solved, but there is still something left.

                  I have no problems at all with my new discovery Chromebook, I can sit now 12-14h a day without problems (this is super shitty quality and flickers like crazy but I don't have issues with flicker).

                  Disabled the smoothing on my Air and Retina too. The Air is much more comfortable now, the Retina is slightly improved but still not good enough :S

                  I also have enabled "Reduce Transparency". This feature on the iPhone X gave me similar improvement to the Retina after disabling smoothing.

                  I noticed that I should not enable "Increase Contrast" as that worsens my situation.

                  I matched the fonts on my Retina chrome with what's on the Chromebook
                  https://www.fontsquirrel.com/fonts/tinos
                  Standard font: Tinos
                  Serif: Tinos
                  Sans-serif: Arimo
                  Fixed-width: Cousine

                  I plug them into x2 same monitors "Lenovo ThinkVision P27h-10 27" and match the resolution 1600x900 (60HZ) but I still can't get the comfort level from the Retina match that of the Chromebook. That external monitor where the Mac Retina is attached still produces much smoother picture (although now can visibly tell anti aliasing is off). I think it has something to do with the color depth/bit depth/buffer frame. Installed SwitchResX and Display Maestro 2 but both of them show only Millions. The Chromebook is maybe in thousands, not sure how to check :S Or maybe its 8 vs 16 vs 24 vs 32 bit

                  • JTL replied to this.

                      JTL
                      This naming is confusing indeed: 8 bits per channel may equal 24 bits per 3 RGB channels, as well as 32 bits per RGB + transparency. I initially thought that 24 and 32 bit screens are different
                      E: I've just checked the link you provided - it says the same thing 😃

                      • JTL likes this.

                        24 vs. 32 bit screens is ALSO misleading - most screens are in fact 18-bit and simulate 24-bit. There are a VERY FEW 30-bit screens.

                        • JTL replied to this.

                          Gurm 30-bit = 10-bit in marketing speak iirc.

                          • Gurm replied to this.

                              JTL Correct. Which, as I said, there are like 5 of. It's frustrating, but most displays are 6/24 bit. This is why every device flickers. 😉

                                oh looks it's not the bit depth that is my second problem but DPI!! Accidentally noticed that under SwitchResX there are HiDPI and same resolution as regular ones, as soon I picked non HiDPI my Mac discomfort lowered (both on the Retina display and the External one).

                                Besides not being able to tolerate "smooth fonts" looks I can't tolerate DPI > 1x
                                https://wiki.archlinux.org/index.php/HiDPI#Chromium_.2F_Google_Chrome

                                Here is output of chrome://gpu/ output from my comfortable chromebook
                                Display(s) Information
                                Info Display[12528934998507520] bounds=[0,0 1241x698], workarea=[0,0 1241x650], scale=1.1, internal.
                                Color space information {primaries:INVALID, transfer:INVALID, matrix:INVALID, range:INVALID}
                                Bits per color component 8
                                Bits per pixel 24
                                Info Display[13702326689085187] bounds=[1241,0 1600x900], workarea=[1241,0 1600x852], scale=1, external.
                                Color space information {primaries_d50_referred: [[0.6663, 0.3285], [0.3202, 0.6144], [0.1480, 0.0513]], transfer:0.0000x + 0.0000 if x < 0.0000 else (1.0000x + 0.0000)**2.2000 + 0.0000, matrix:RGB, range:FULL}
                                Bits per color component 8
                                Bits per pixel 24

                                At this point I use same external monitors, same font, no smoothing, DPI scale 1 and the Mac still gives me slight discomfort, it's has slight blurness, however I would say 95+% my situation has been improved 😃

                                Looks if iPhone X feels worse than iPhone 8 then it's the DPI, DOES SIZE MATTER? section on this link
                                https://www.zdnet.com/article/iphone-x-or-iphone-8-price-size-camera-all-factor-in-your-buying-decision/
                                as it has higher scale.

                                • hpst replied to this.

                                  Im thinking about this and it makes quite a lot of sense. Imagine when some mentioned that older OS on a good comfortable phone was ok and new one wasnt. Maybe the font rendering in that new update changed, the fonts are more blurry and impossible to fix your vision onto, thus the issues.
                                  Or of course dithering which is still hard to prove and Im not sure why it would change inbetween software updates, but it could of course.
                                  If every outline of every box, font and image is anti-aliased (blurry), then it would makes sense how we feel "unable to focus" most of the time. Its very simple, easily overlooked and for example on iphones impossible to fix. Supposedly though you can change fonts on jailbroken iphone, would be a good idea to try that.
                                  Technically also if you have the same OS on an older and newer iphone, the OS still knows which iteration of iphone it is and could therefore still render differently between those two devices.

                                  dev