# 60Hz causes eye strain and headaches.



## Icebreak (Sep 29, 2003)

Several years ago a co-worker asked if I was getting headaches in the afternoon. I said, "a little bit." I'm not prone to headaches or sickness of any kind and I'm thankful for it. I was feeling some pressure in my forehead in the afternoon. Well the co-worker fixed it by changing the refresh rate on my monitor...no more pressure. I never forgot that.

I want to advocate a policy change at work. I’m sure that the flickering that causes eyestrain and headaches can’t be good and the fix is easy. I Googled around and found some good information but not the definitive, trusted documentation I was looking for. I used combinations of AMA, Lancet, Hz, etc. I got quite a few hits on "refresh rate headaches". Here is a link to a forum that links to another forum: XtremeModsArticle It's a good article but I'm looking for something from the medical community.

Many people can’t see the flicker at 60hz. To me it is very pronounced. I can see the flicker all the way up to 72hz. At 75hz I can no long see it but I can feel it…hard to describe. 85hz feels much better. My home machine is set at 100hz. 120hz doesn’t seem any different. This Hansol monitor can handle it but I wouldn’t recommend going over 85hz unless you are sure your monitor can handle it.

So here are my questions.

Have you ever noticed this?

Did you change your monitor settings?

What do you think about this?

Does anybody have any documentation from the medical community I can use to support my advocacy?

Thanks.


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## RevDavid (Sep 29, 2003)

I am feeling worse just reading this...
Hopefully it is just the power of suggestion.

btw... doesn't your ear itch? /ubbthreads/images/graemlins/yellowlaugh.gif

See what I mean? /ubbthreads/images/graemlins/rolleyes.gif

David <><


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## jtice (Sep 29, 2003)

A monitor at 60Hz drives me NUTS!!!!

I like it at least up to 75Hz.

I have a few floresent lights also, those will go crazy with a monitor at 60Hz.


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## Tomas (Sep 29, 2003)

My monitor refresh rate is 75Hz, TV's have a field refresh rate of 60Hz (frame refresh rate of 30Hz), theatre movies have a frame rate of 24 Hz, and common fluorescents flicker rate of 120 Hz. 

One of the reasons TV's don't bother people as much even though their refresh is so slow is 'long persistance phosphors.' (Not as long as the twin-phosphors in my old Tektronics scope, though. The quick phosphor (blue) is just like a computer: Quick, but the long persistance phosphor (green) holds an image for around 5 seconds. That's so you can examine a trace in more detail. Newer 'scopes use digital memory rather than the strange phosphors of the older analogs.)

Computer monitors designed for slower refresh rates generally have slower phosphors, too ... less flicker. 

A monitor not designed for slow refresh will flicker a lot, and really be annoying.

I don't know of any current studies on the effects, but in spec'ing CRT's the phosphor persistance is a primary feature - or at least it used to be. (Been too long since I did that sort of thing.)


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## eluminator (Sep 29, 2003)

I've noticed that some people can see the flicker with a 60 Hertz refresh and some cannot. I can't, but I run the refresh higher than 60 anyway.

I guess the flat panel monitors don't have this problem. Anyway I liked my $650 flat panel so much I bought a second one. This one I got for $500. I'll never buy another CRT. 

And I'm tight with my money too. I don't own a Surefire and my Arc LS is a factory second. 

Incidentally, for those who might not know, a 17 inch flat panel has the same size screen as an 18 inch CRT.


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## Kristofg (Sep 29, 2003)

The easiest way to see the flicker is looking not at the screen itself but to a point next to the screen zo that you see the screen from the corner of your eye. You should try iy at a TV store. It's amazing how easy it is to spot the difference between 100Hz tv sets and normal tv sets this way.


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## James S (Sep 29, 2003)

I agree completely, why do so many computer monitors ship with a default resolution and scan rate that is so miserable? And why don't more IT departments setup their machines at a higher scan rate? I can't tell you how many offices I have walked into that all have recent monitors that could run at least 75htz and I see whole rows of them flickering away at 60htz.

I don't think you can buy a monitor today that doesn't so better than that. Do yourself a favor and tweak it up, you'll feel better. 

Flatscreens are even better, a good flatscreen is awesome. Since using the excellent screens that Apple ships on these powerbooks I will never go back to a CRT.


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## BuddTX (Sep 29, 2003)

[ QUOTE ]
*Icebreak said:*/showthread/t-1689.html]XtremeModsArticle 

[/ QUOTE ]

The link does not work.

I think you are trying to link to these two sites:

Xtreme Mods 

and

PC TECH TALK


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## BuddTX (Sep 29, 2003)

Another good article


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## _mike_ (Sep 29, 2003)

I bumped my refresh rate up to 85Hz, but as stated previously....your monitor may not handle going above 85Hz. Heck....if your monitor is really old it may not handle anything over 75Hz. 

Also, the fluorescent overhead lighting can add to the problem because they flicker as well. Sooo...you have a 60Hz refresh rate along with your lighting flickering, you may wind up going through lots of aspirin. They do have different balasts and fluorescent lights that have a "virtually imperceptible" flicker. They installed that type of lighting at the University of Washington several years ago because of the headache and eye fatigue thing....took them a few years to get all the office lights done because there were so many.

Mike


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## LEDmodMan (Sep 29, 2003)

Yes, this drives me crazy!!! I can instantly see flicker at 60Hz, as thus I immediately adjust any screen I'm using to at least 75Hz, higher if it will handle it. My desktop screen here at work has been set at 85Hz since my first day! /ubbthreads/images/graemlins/grin.gif

It's funny how it is very pronounced to some people, and how others can't even see it. I guess that's kinda like how some people can hear higher and lower frequencies than others can.


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## Chris M. (Sep 29, 2003)

You think you`ve got it bad. Here in the UK our TVs flicker at 50Hz /ubbthreads/images/graemlins/eek.gif . At least my big old NEC Multisync will handle 85Hz at 1024x768. 

Thankfully high frequency control gear for flourescent lighting is becoming more common. Get a bad/aging tube on an old iron ballast and it`ll flicker at 50Hz too.......

/ubbthreads/images/graemlins/icon15.gif


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## Icebreak (Sep 29, 2003)

RevDavid -

Actually my nose started to itch on the left side then on the right side...See what I mean? /ubbthreads/images/graemlins/smile.gif

BuddTx -

Thanks for the links.

All -

It seems like from what I'm hearing I should look into high frequency ballasts for all these fluourescent tubes around here.


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## binky (Sep 29, 2003)

I write code & read documents (don't surf nope of course never /ubbthreads/images/graemlins/wink.gif) at least all day long. CRT refresh annoys me too. I need at least 75Hz minimum. But I've gone LCD & I'll never go back. It also gives much sharper text than any CRT technology so it's far easier on the eyes for that reason too.

If you can convince your company to go LCD you'll be lovin' it!

BTW, they usually use far less power than the CRT's. Maybe that's one other "selling point"?


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## The_LED_Museum (Sep 29, 2003)

I just checked my Dell with a 19" Trinitron boob tube, and it's set to 75Hz. I've never noticed any flickering. And I tried that technique of "looking at" the monitor from the corner of my eye, and still note no flickering.
One of my old monitors though, flickered noticeably when set to 72Hz. So either the 3Hz difference is noticeable, or the newer monitor has a longer persistence phosphor than the old one did.


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## snakebite (Sep 29, 2003)

i work in a computer store part of the day.
nothing irritates me more than a monitor still set at the default 60hz refresh under iron ballast flourescents.
i immediatly adjust them to at least 75 if possible.


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## Icebreak (Sep 29, 2003)

binky -

You may really have something there. The organization I work for is strong on worker health. Recently, one of the squeekiest programmers convinced them to spend a fortune on ergonomically correct chairs. When I say fortune I'm talking over $500.00 per chair. An extra power strip? Good luck.

I'll need to become a better researcher. If I can't do any good on medical documentation I may have to try *<font color="green">B</font>*ionic *<font color="green">A</font>*rticulating *<font color="green">R</font>*etrieval *<font color="green">T</font>*echnology.

Really good idea, binky. Thanks.

Craig -

As others have pointed out; I find it interesting that some people can see the flicker and others cannot.


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## iddibhai (Sep 30, 2003)

i can see the flicker at 60, sometimes 72. home machine runs at 85 (highest safe refresh for screen res)


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## chamenos (Sep 30, 2003)

i have my monitor set at 85hz, at a resolution of 1152x864. anything below 75hz and i start getting a headache. btw, LCD monitors may not have any flickering, but they generally have a slower refresh rate, which means a slower frame rate which won't be good if you're playing games or something.


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## Quickbeam (Sep 30, 2003)

60Hz monitors drive me bonkers. As my eyes get tired I can definately see the flicker of overhead fluorescent lights out of the corner of my eyes, too.

Even at 75Hz my eyes were bugging me, so we broke down and bought an LCD. My eyes feel SO much better now.

My LCD plays video games just like a CRT. No slow refresh rate here! Slow LCD refreshes were a problem with older models. Newer ones are quite clear even with rapid movement of the screen picture.


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