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  • StefanD13 Level 1 Level 1

    Wow, nice Post Kxtr73. As CoreLinker explained to me prviously, the FRC dithering is nowadays always there, even for 8bit panels in order to better cover the color space.

    So maybe that’s why you couldn’t completely eliminate your symptoms.


    As an update from my side, I have ordered (again) the surface rt and probably will also keep it. It is usable for an hour or two a day without big issues. However what I also noticed is that my symptoms appear much sooner if I watch pictures or some other color rich content on the surface rt. So looks like the Tegra3 reduces the dithering if less colours are needed.



  • Kxtr73 Level 1 Level 1

    Jessiah1 wrote:


    (...) One question I have for you: Did you have issues with lighting before all of your testing or do you think they became much worse afterwards?(..)

    I haven't any problems before. After a few days with 27' LED screen my right eye was in pain in 3 weeks and had blurred vision .... Then everything back to normal. After using about 3 weeks 32' TV/monitor with fluorescent EEFL (from previous post) both eyes are irritated, but they recover well.


    Jessiah1 wrote:


    Take a look at this slow motion video of an LED light bulb and share your thought's on that as well!


    WARNING: If you are very sensitive this will have an effect on you, I can only watch it for 10 seconds!


    I have 2,5 Watt LED bulb with PWM in my kitchen, but have no problem with it even now.

    It shines from above out of sight. I use some LED backlith devices without PWM with easy. But all of them don't use so many diodes like 27' LCD/LED LG monitor. For me backlight light intensity is the problem. In my tests I always used the same very moderate screen lightness. Before reducing baclight electric current they worked with 100% power so I dimmed them by 0% contrast = severe burning. After reducing EEFL light current (dimmed by twice) and adding 2 mm PMMA sheet indide panel I had to change contrast to 60% to achieve the same visible screen backlight. But this time eyes irritation was much smaller and after some time. Joke is in the same time I can use other 24' CCFL monitor with even greater lightness without any problems ..... but only a few seconds of looking to 32' EEFL creates pain.



    Wow, nice Post Kxtr73. As CoreLinker explained to me prviously, the FRC dithering is nowadays always there, even for 8bit panels in order to better cover the color space. So maybe that’s why you couldn’t completely eliminate your symptoms.

    So I understand now the LG panel datasheet: 8 BIT /  8 BIT/FRC. But I don't see any FRC color change vs my other 24 TN 6 BIT panel which has visible sometimes FRC but is very comfortable. I think or the size of 32' matters, or EEFL is much different then CCFL (EEFL uses magnetic induction and is very similar to normal fluorescent bulb) or rear placement of bulbs behind the screen are worse then edge placement.

  • LovesDogs0415 Level 1 Level 1

    I know that people on this forum suffer while using many Apple devices.  I just purchased an iphone 4S and it is hurting my eyes and causing all kinds of the common symptoms.  Please, if any of you have successfully used any smartphone, PLEASE tell me.  I have just a few days to return before an out of town trip.


    Also, I was going to try flux, but can't figure out all the jailbreaking stuff to install.  Any advice?


    Deeply grateful.

  • Jessiah1 Level 1 Level 1

    I just purchased an Iphone 4 to replace my old 4 because some buttons were not working. The 4S is where LED back lighting started, the 5S is much worse than the 4S. If I wear my anti-glare coated glasses I can look at an Iphone 4 all day without any issues, hope this helps!

  • Gurm42 Level 1 Level 1



    That's not entirely correct. All the retina displays (the 4 was a retina!) have been LED backlit. Even the 3G was, I think LED backlit.


    But they were the good, yellow LED's not the terrible blue ones.


    My iPhone 4S actually has good LED's! It's noticeably yellower than the ones my coworkers have.

  • Jessiah1 Level 1 Level 1

    Interesting, I am starting to realize that is probably true at least with my replacement phone. I think there is a chance my old 4 was not or at least better LED bulbs as you have stated? This new one is bothering me a bit even with my glass's and I have been having more consistent eyestrain headaches since I bought it, it's no where close to as bad as my wifes 4S or any 5 I have been around but it is bothering me a little. Still, it is the most tolerable for me regardless....and there are no more options if you love the Iphone...

  • LovesDogs0415 Level 1 Level 1

    Any smartphone, not just Apple.  Has anyone had any luck with other manufacturers.    I may try to switch to the 4 if that is supposed to be better, but I am open to other manufacturers.  Apple doesn't care about this and so my loyalty is not appreciated.

  • mvanier Level 1 Level 1

    All iPhones, even the oldest ones, are LED backlit.  You can't use a CCFL backlight in a phone; it's way too large and would use up all the power in nothing flat.  However, as people have observed, some LEDs are yellower than others, and the yellower they are, the less eyestrain.  I think this is a semi-random phenomenon based on which lot the LEDs came from.  Some smartphones use AMOLED screens which are not backlit at all (the LED pixels produce their own light); I have no idea if these are easier on the eyes or not.

  • David Turnough Level 1 Level 1

    On the whole, I find AMOLED screens much much worse. I can't even look at the recent Samsung Flagships. I'm not sure if my eyes are getting worse too, as I'm even avoiding my HTC OneX, which previously didn't irritate me.

  • Kxtr73 Level 1 Level 1

    I made more tests with my AKAI 32 IPS TV/monitor with LG display backlighted by rear placed 14 EEFL bulbs. Finally - success !


    As I wrote before after removing PWM my eyes stopped to be tired but eye burning sensation was still there.

    Even staring at black screen was not helping. Why ? Becouse LCD matrix always bleed some backlight light. I realized that this type of fluorescent probably is emitting too high peak in blue light.


    1. changed in TV service menu in RGB video settings "B" (blue) to 0. No more blue on my scree. Easier to eyes, but backlight bleeding is still passing some light with full fluorescent spectra. When your eyes are irritated even the smallest bad factor is the problem.


    2. Again I tried 2 cm yellow PMMA (with UV blocker) inside LCD panel which is blocking all blue spectrum of EEFL. Now after longer tests I see that it works. (Normal yellow thinted glasses or yellow ski googles was transitted some blue thus not working for me with that screen) After hours of work no more eyes burning. The problem is - my diplay is yellow now. I must find filter which is dimming partially blue peak to normal levels without general disscolorisation.


    The spectra of all fluorescent and LED are high in blue, so without proper protection are eyes will suffer now or later.

  • Spock66 Level 1 Level 1

    I'm from Sweden and had never had problems with monitors until i got an ipad 3. It felt like someone had stuck a knife in the left eye after a period of use.

    I tried to pull down the light, matte screen protector and f.lux but nothing helped and the pain just got worse and worse.

    I also got strange motion sickness-like symptoms

    I contacted an ophthalmologist and had my eyes checked, but he could not find anything wrong and i had perfect vision in both eyes.

    Eventually, i sold the ipad.

    But the story does not end there.

    I bought a new LG Led tv and then the problems started again.

    If I have a lot of lights on around the TV, i can cope with a movie with almost no pain. But if it´s dark in the

    room, it only takes about 10min before the left eye begins to give up.

    I have also had problems with some mobile phones.


    Sony Xperia: A little pain after a while.

    HTC Mozart: Very sore eye.

    Samsung Galaxy SII: No problems at all, no matter how long i use it.


    I also bought a led computer monitor, but my eye didn´t like it, so i sold it.

    So now i have a old 2209wa ccfl monitor to the computer and a Galaxy s2 Mobile Phone and my eyes feels very healthy again

    The problem is that it takes along time for the eye/eyes to recover after a long look in a led screen.

    When it was at its worst, i could not even look at a ccfl monitor/tv.

    For over a week i had to rest my eyes from all monitors/tv before i could look at them again.


    Today i borrowed an ipad 4 from a friend. From the beginning it felt quite ok.

    But after i while the burning sensation started in the eye.

    But i was not aware of any motion sickness i got with ipad 3

    It's faster scrolling, minimal lag and very little ghosting on ipad 4.

    So it felt much more comfortable than Ipad 3.

    But I hope the manufacturers of screens takes the problem seriously and do something

    about it, for something is very wrong with the led backlight technology.

    I would love to be able to use an Ipad or any new computer technology without having serious

    eye problems.

    I dare hardly buy anything new, because i do not know if I can use it: (


  • Spock66 Level 1 Level 1

    Very intresting report. I have read about the problem with blue light and pwm.

    But i can´t understand why the manufactures dosen´t have done something

    about the problem?

    I know that Benq have a new monitor with no pwm dimming. But the question is,

    is it enough to cure the problem when the blue light still is there?

    They must probably also come up with a new filter technology to solve the problem altogether.

  • Kxtr73 Level 1 Level 1

    Eizo published report: The Latest on Computer Screens and Eye Fatigue


    My comments:

    Subject 1: LED Backlight

    - DC Dimming Cons: (...)Complicated circuitry

    completely not true, current dimming is older and easier technique then PWM dimming. Most driving chips in backlight inverters has the option to analog dimming, so even user with some knowledge of electronics could rework any monitor or TV from PWM to DC dimming for free.


    Subject 3: Blue Light

    Problem is the LCD matrix always bleed some light from backlight which passes between crystals.

    The filter cutting blue light peak should be installed before the matrix. Anyway something is much different in LCD vs CRT technology. I can look 24 hours/day in pure blue CRT screen without disscomfort, when some LCD CCFL/EEFL or LED (PWM free too) without any blue on display stress my eyes rapidly.


    In fact having spectrometer and some others measuring tools + volunteers with sensitive eyes and  producer could localize where exactly the problems are. It's not such complicated. It only requires good will.


    So my attention: if your eyes feel uncomfortable is better to stop using this particular LCD screen for the good of your eyes. Eyesight is priceless.

  • Kxtr73 Level 1 Level 1

    Today after many hours of work I reworked my backlighted by fluorescent EEFL lamps 32 TV/monitor to halogen backlight. Wow. It's so soft to eyes with such vibrant and natural colours. Yes - there is a white colour. Screen is not yellow. Mayby with a little natural sunlight yellow tint.


    As I wrote before I tried to to make it comfortable by analog backlight driving and by adding colour filters to make fluorescent light better. Yes it was better. My eyes simply burned not so much as before and at morning pain was easier to withstand. But it's false path. Yesterday I've felt burning after a minute of watching this eye killer. Today after many hours of watching and surfing net on halogen backlight I must say - I feel nothing. It's even better then CRT. It's like watching an image from projector or watching gently backlighted sheet of paper. I could even watch it even from a few centimeters without any evil sensation.


    Now after successul tests with external 25 Watt halogen I will put a few 10 Watts inside + probably low noise fan, so from exterior it will have the same look as oryginal. Yes there is a hope - hope has the name - standard incandascent bulb in form of 12 V bathroom halogen. Of course it eat some more power (I think 60-80 Watt in 32') and could be utilized in rather stationary monitors/TV but in fact reworking to halogen it's not such hard. Soon photos. Hurrey.

  • Eric Leung1 Level 1 Level 1

    Kxtr73, you have awesome skills!

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