Eyestrain and The MBA 11": My Experience and Feedback Requested

[MyMcMac]

part of the problem for me, i think, is the LED backlighting, brightness being one issue. i read that LEDs are hard to dim, so what they would do is have them flash on and off at a high frequency, to simulate, say 50% brightness. supposedly some people are more sensitive to this and the flashing results in eyestrain, headaches, etc. however, i don't know if this method is still used, or if its used on the MBA

Mojo1, I think not the pixel density is a problem for you. It is the flickering or the way pixels are displayed to you.

Flickering is the on and off of the background led. Typical leds flicker at a high frequency, although a low frequency is used in cheaper background led backlights. You can't see the flicker as your eyes can not see anything higher than around 100 Hz (100 images per minute). But your eyes can adapt to dark and bright up to a much higher frequency. In this case, while you see nothing going on, your eyes are working tremendously. This gives you a headache.

Also the way pixels are displayed to you is important. How is the layer above the panel (anti-glare, only a little bit anti-glare)? All matte displays have this additional layer. And likely the airs because they are not really glare. There are lots of different approaches of displaying pixels as TN (used in the air), MVA, IPS and so on. Within these approaches, you find also differences.

 

[gerabbi]

gerabbi, which method(s) do you use to increase the font size?

After reading some other threads: TinkerTool does let you modify the fonts in several different ways. It may be worth a quick download and some tinkering with it to see if it may help some with the font size issue, ymmv.

 

[Mojo1]

Mojo1, I think not the pixel density is a problem for you. It is the flickering or the way pixels are displayed to you.

Flickering is the on and off of the background led. Typical leds flicker at a high frequency, although a low frequency is used in cheaper background led backlights. You can't see the flicker as your eyes can not see anything higher than around 100 Hz (100 images per minute). But your eyes can adapt to dark and bright up to a much higher frequency. In this case, while you see nothing going on, your eyes are working tremendously. This gives you a headache.

Also the way pixels are displayed to you is important. How is the layer above the panel (anti-glare, only a little bit anti-glare)? All matte displays have this additional layer. And likely the airs because they are not really glare. There are lots of different approaches of displaying pixels as TN (used in the air), MVA, IPS and so on. Within these approaches, you find also differences.

Hmmm... interesting!

I just checked and my 15" MBP also has an LED, albeit a matte display. I've never had a problem using it.

Can the difference be the somewhat glossy MBA vs. the matte MBP display? Or is something else going on, such as the LED flickering combined with the pixel density? (The MBP has a 1440x900 display: http://www.everymac.com/systems/app...ore-2-duo-2.4-15-early-2008-penryn-specs.html)

I'm just trying to figure out where to go from here: I'm in the market for a new portable Mac and it's discouraging to have run into this problem with the 11".

My wife and I are going to visit our local computer store this afternoon so she can add her two cents to this debate...

UPDATE: I may have saved myself a trip to the computer store... I spent a little time researching this problem and it turns out that I am not the only person experiencing this problem with current Apple displays: https://discussions.apple.com/thread/1677617?start=0&tstart=0

 

[Mojo1]

Visited The Computer Store...

... and my wife noticed a problem too, and she used the MBA for <10 minutes.

The store just happened to have a matte screen 15" MBP. No problem there...

I think that it must be the LED display, so I think that the MBAs are simply a non-starter for me. Apple must be using lower quality displays in the MBAs.

If I get an MBP 13" I would install a matte display from Tech Restore. I'm waiting to hear from them regarding what display they use and what they expect to use in the upcoming MBA retrofit display.

 

[VMMan]

Headaches are referred to as a nonspecific symptom (i.e. an extremely wide variety of different factors can cause them).

I would spend more time with them, in the store, borrow a friends, or take the plunge and buy the 11" since you seem to want that one if it were not for the headache.

No amount of speculation on this forum is a substitute for trying it out, assuming you aren't having headaches currently even without any computer use.

Also, it took me a couple of days getting used to the MBA 11" screen.

 

[lcseds]

I was at the local Apple store yesterday test driving the MBA's. After about 20 minutes I had a headache. Not sure if it was the MBA displays or the incredible level of noise in the store. The Apple store on a weekend is nearly unbearable.

 

[MyMcMac]

Mojo1, in most cases these symptoms are because of backlight flickering. Some manufactures even adapt the flickering to increase color accuracy. This is all possible, but if your eyes adapt to the flicker, you are getting a headache and your eyes will have problems. You can not see this as in any movie you don't see the breaks between the images or the images alone.

From what I know, cheap leds or low power leds have lower HZ which results in a refresh rate where eyes can adapt to. This causes problems.

 

[Mojo1]

Headaches are referred to as a nonspecific symptom (i.e. an extremely wide variety of different factors can cause them).

We can attempt to deny that the MBA screens were the cause of my headache and eyestrain (see the post from the person who visited an Apple store...) but I am convinced that it is a problem with the displays. Prior to the store visit I did not have a headache nor a reason to develop one.

From the start I had a problem focusing on the display and it simply did not feel right. I have worked on a variety of computer displays over the years and this is the first time that I have had this experience with an LCD display. Years ago I did experience mild eyestrain with some CRT displays, but only after hours of use during the day.

Until now I have preferred LCD displays over CRTs primarily because I did not experience eyestrain after sitting in front of one all day long. But my experience has been with relatively high quality matte displays.

I would spend more time with them, in the store, borrow a friends, or take the plunge and buy the 11" since you seem to want that one if it were not for the headache.

I would like an 11" but I don't want one THAT much... I'd be inclined to go that route if it wasn't for all the similar experiences posted on the Apple forum and elsewhere on the Internet.

No amount of speculation on this forum is a substitute for trying it out, assuming you aren't having headaches currently even without any computer use.

I think that we are beyond speculation at this point. My experience has been confirmed multiple times. I posted my query here only to find out if anyone else had a similar experience. We can speculate regarding the causes of the eyestrain/headache, but I don't doubt the veracity of user reports and my own experience.

Obviously, sensitivity to some LED-backlit displays is subjective: apparently many people have no problem while others cannot abide them. The displays that my wife and I looked at were not visibly defective; they actually looked better than I expected after reading some of the comments on this forum. But after only a few minutes my wife said "Something is not right with these displays." She uses our MBP for hours at a time, so she has some first-hand experience with Apple displays.

I prefer matte displays but I have worked on clients' glassy iMacs without problems, albeit for relatively short periods of time (up to two hours). I think that the MBA reflectivity is much less than the glassy MBP displays, so much better in fact that I thought that it wouldn't be a problem for me. But I think that there is another problem that probably has nothing to do with the reflectivity, probably the LED backlight and the refresh rate.

 

[bill-p]

Or it could just be simply that, you know, the 11" MBA pixel density is too high, which results in tiny texts and even smaller details on graphical elements, causing eyestrain since your eyes "think" there is more to be seen.

I don't know about LED-theorists, but surely if LED baclighting was the main cause, you'd have a headache looking at your MBP, too. Matte just reduces glare on screen, it doesn't magically make LED any more pleasant.

 

[jsolares]

I prefer matte displays but I have worked on clients' glassy iMacs without problems, albeit for relatively short periods of time (up to two hours). I think that the MBA reflectivity is much less than the glassy MBP displays, so much better in fact that I thought that it wouldn't be a problem for me. But I think that there is another problem that probably has nothing to do with the reflectivity, probably the LED backlight and the refresh rate.

The new iMacs? my 2010 also has some flickering since it's also a LED backlight, i've started to notice it lately, or maybe ignored it for quite a while.. (the lightbulb in my room seems to be dying, and it has no windows so it's quite dim and more so now), i do get some eyestrain but no headache, i guess i can see it but i'm not that sensitive to it. it almost feels like i need new glasses as if my astigmatism has gotten worse.

With the air i see no difference except that it's a bit dull color wise. i think i'm gonna go hook up my old crappy (it looks like crap next to the iMac color wise) 22" LCD i think it's CCFL and see if i get less eyestrain.

 

[slpslee]

Mojo1, your eyes sound much like mine, except my retina hasn't detached (and I'm keeping my fingers crossed that it won't). I spend many hours a day using a computer, including a minimum of 8 hours at work. I really wanted the 11" MBA for the portability factor alone, but I worried about the screen size. I also have a 15" MBP, so I figured that, worst case scenario, I'd just continue to carry the MBP to work and use the Air more like a netbook. It turned out I worried unnecessarily. The 11" Air with Lion is more than capable as an everyday computer, even to aging eyes (or, in my case, already well aged). Mine has the LG display but I honestly don't see anything to complain about.

For all that, I don't see where a person could go very far wrong choosing either model. I liked the 13" MBA, too--it just wasn't that much different from my MBP as far as size was concerned.

 

[meistervu]

Mojo1, it's fascinating to me that you experienced similar symtoms that I did when I tested the MBA in store. I still don't know what the reasons were for me, but I am glad to say that the problems were gone when I used the MBA 13" at home, in coffee shops, or at a friend's house. I am not trying to tell you that your problem will go away outside the store. I just want to relate my personal experience because you asked for it.

First, a bit about my background. I have used many different type of screens, from CGA to 21" CRT, LCDs with CCFL and with LED back lights. I personally doubt the claim of LED back light dimming by rapidly turning off and on causing headache. I can see the flicker in cheap LED christmas lights, but I can't in LED back light. I think the modulation is much faster than the 60Hz or whatever in the cheap christmas lights.

I don't know the true cause of eyestrain and headache I experienced in the store, but I have a few theories:

1. perfume - I often get headache when I spend more than a couple of hours shopping in certain crowded places. It doesn't happen in a sporting goods store like REI, perhaps because I like the stuff they sell there, but I suspect it has to do with the perfumes that other people wear. This might not have been the case for you because it appeared that you went at a less crowded time.

2. too much focus - staring a a screen in trying to decide whether it looks good for a good period of time is unnatural and can cause a lot of eyestrain and headache, as it requires a lot more visual focus and brain processing, plus I have the tendency of not blinking as often as I would normally when I focus too much on what's displayed on the screen, and that alone contributes to eyestrain and headache. I only am aware of this because my eye doctor observed it on me during a visit. When one uses a computer in a normal setting, it doesn't take much effort to scan and read text (unless you are reading a language you are not fluent in), hence a lot less strain.

So I believe that the real test is to use the computer how you normally use it. Forget about all the theories about what cause eyes strain, LED versus CCFL back lights, text sizes. Just use it for a day and find out for yourself. And no one can take this test for you. Also, I would not allow what other people wrote online alone to influence my own decision making. This includes my own advice above. If you don't think it's worth the time to pick up a MBA
and try it out for a day knowing that you can return within 2 weeks with no obligation, then don't do it.

 

[Mojo1]

I appreciate the feedback guys. But I'm not just basing my decision on what I have read online. If I hadn't had the experience that I had I wouldn't have known anything more about LED displays than what I have read in passing regarding energy-savings and color accuracy.

There is a difference between displays, quality-wise. The reflectivity of a display makes a difference in its usability under certain lighting conditions, as well as being a problem for some folks no matter what the working environment night be. Sitting in front of a display like an iMac is similar to looking at oneself in a mirror even in a darkened room; wear some light clothing and you can knot a tie without any problem.

In my profession I have had to deal with all kinds of lighting in myriad environments, so I have had to learn a lot about the quality of various light sources and how to mitigate the negative effects of certain light sources.

Fluorescent lighting is not constant. It operates at cycling frequencies that are imperceptible unless there is a defect in the ballast and then it can be readily visible.

Take your typical fluorescent fixtures found in offices... Snap a picture at 125th/second or slower and the image will usually turn out fine. But bump the shutter speed up a notch or two and the image will have light and dark bands running from top to bottom; simply put, that's the light cycling on and off. Our brain usually compensates for this so we aren't even aware of it. But the eyes and brain react to the cycling more or less depending on the quality of the fluorescent fixture, and some lights cause problems for some people.

LEDs cycle on and off too. They also operate in a different range of the color spectrum than fluorescent lights, which makes them more desirable for certain applications. (There are other benefits too.) As LEDs have become more commonly used for things such as computer displays, it has become apparent that some people can have problems using LED-backlit light sources. It may be due to the refresh rate or the LED bulb colors, or a combination of these two factors. I think that display reflectivity also plays a part in this. There may even be serious eye damage possible due to the "blue-light effect." (Google the term if you are interested.)

Since LED displays can be too bright at the brightest setting or drain batteries faster than is desirable, users often dial-down the brightness. Doing so can exacerbate eyestrain because of how reducing brightness affects the refresh rate of the LEDs.

The bottom line is we simply don't know the long-term effects of LED displays since they haven't been used for all that long in displays. And we don't fully understand why some people are more sensitive to LEDs. I'm sure that we'll learn some things that we did not anticipate as we continue to gather data via studies and real-life experience.

At this point I doubt that simply changing the viewing environment or giving my eyes time to "adjust" is going to improve things for me. It's going to be rather difficult to use a display long enough to see if it gets better if I develop a headache within the first ten minutes of use. At this point I don't actually need a new portable Mac, so I have time to think this over and look into this some more. When push comes to shove I can always order an MBA and return it if it turns out that I cannot use it due to the display. Or I can replace the display on an MBA or MBp with a matte screen in the hope that it will be an improvement over the stock display.

Again, thanks for the feedback and suggestions. If anyone has something to add that hasn't already been said, I'm all ears!

 

[meistervu]

LED back light

I have done some research in the past regarding LED dimming for general lighting as it turns out to be my one of my hobbies. Many of my friends would consider me a lighting fanatic.

AFAIK, all commercial LED dims by turning off and on at certain frequency (modulation). Personally, I have tried many dimming LED lamps, and good dimmable ones dimmed really well without perceivable flickers. On the other hands, there are bad ones out there that did not dim so well.

The same is true for CCFL which is the older type of LCD back light. I have tried a few CCFL lamps, and the bad ones are really bad: they flickers really badly when dimmed. Plus they all takes some time to warm up and produce full brightness, unlike LED.

Without a doubt, back light in LCD are much better engineered than typical household light bulbs, but the general idea is the same.

For my money, I would not buy a LCD with a CCFL back light now a day. Good LED back light provides better color gamut, more even lighting, no warm up time, and longer life with little light degradation, not to mention less battery drain.