5 replies to this topic

[j03]

I read this article about screen flickering: http://crispycromar....raine-headaches and it was very enlightening. I always assumed that lowering the screen brightness would reduce the eyestrain but infact reducing the brightness increased the backlight flickering. You can test the amount of flickering your monitor does by putting a camera with an led screen to your computer monitor (I used my cell phone cam) and seeing if there's any flickering or a wave like effect.

Anyways, I increased the screen brightness to full and found this little program to dim the screen: http://www.softpedia...imScreen.shtml. I set that at 50% and tested it with my cell phone. No screen flickering, and most importantly no headaches since!!

I also use the program flu.x and the two of them combined has made my eye strain go away. I just thought I would share this, as i know there's other here suffering from the same malaise as me (migraines).

[Baten]

Neat little test. My screen seems to barely flicker at all, so I guess I'm safe.

I use a low brightness setting coupled with the flux application (which is truly godsend).

Edited by Baten, 25 February 2012 - 07:20 PM.

[j03]

Neat little test. My screen seems to barely flicker at all, so I guess I'm safe.

I use a low brightness setting coupled with the flux application (which is truly godsend).

My screen flickered a little bit with the dimmed light setting, but that was enough to trigger a migraine.

I find that dimscreen program + flu.x to be a nice combination.

[MrHappy]

I agree - f.lux is awesome, I use it on my iphone to reduce blue light output and keep my circadian rhythms healthy.

Regarding 'flicker' perhaps some more detail will be helpful - on LCDs, there are potentially 2 sources of flicker. The first is preset, but often adjustable. It's also known as the 'refresh rate' or 'horizontal frequency' from the old CRT days.

In the US, TVs and monitors are set to 60hz, same as the powerline frequency. In Australia and most/all of Europe, that frequency is lower, at 50hz.

Normally, if you can see your LCD 'flicker' via your mobile phone / camera, that just means that it is preset to the other frequency. Webcams have an option to choose between the 2 for 'antiflicker'.

The brightness/backlighting on LCDs has, until somewhat recently, been created by miniature fluorescent tubes, but is now generally created by white LEDs. The old fluoro tubes may exhibit some flicker at lower brightness levels. The new LEDs don't - they're powered by DC voltages, so no powerline frequency flickering.

If you are getting eyestrain, f.lux is awesome and upgrading to a new LED backlit LCD should finish the job.

[nupi]

LCDs connected through digital channels (DVI/HDMI/DisplayPort/Laptop screens) should not suffer of any refresh rate syncing issues. LED backlights eliminate the remainder of the flickering, yes.

[MrHappy]

Correct, Nupi - the comment previously made suggesting to 'use your phone to see the flicker' was why I added all the info. There is no guarantee the phone/camera refresh rate matches the screen you are testing, so this won't be always be helpful.