I've been sat in front of "Television" Monitor screens, CRT Monitor screens and LCD Monitor screens for around 18 hours per day for the past 26 years*...!
The problem is, my eyes get used to the fixed focus distance, and this causes my eyes to get very tired, and I have to close them regularly to rest them...
It takes a while to re-focus on a distance..!
I used to be concerned about the radiation effects over time, but so far I don't think that has has any effect on my eyes...
..they just get
VERY tired...

...!!!
Paul....must get out more...

...

...!
* Computer programmer in the early days of Personal Computers....Sinclair Spectrum, Commodore 64, Amstrad CPC, Amiga 1200, etc, etc...

...!
Win 8.1 64-bit. DX11. Advent Tower. Intel i7-3770 3.9 GHz 8-core. 8 GB System RAM. AMD Radeon HD 7700 1GB RAM. DVD ROM. 2 Terra Byte SATA Hard Drive. Philips 17" LCD Monitor. Saitek Cyborg X Fly-5 Joystick. ...and a Briggs and Stratton Petrol Lawn Mower.