Two monitors: Samsung T23C350 - Samsung 2243NW

Lets call the first A and the other B.

A is a LED monitor with a 2ms response time (in specs) with a native resolution of 1920*1080@60Hz

B is an older not-led one with 5ms response in specs with a resolution of 1680*1050@60Hz

In the attached images and video you'll see that A (on the LEFT) is flickering but this is not visible to the naked eye.

I took some pictures and videos with a camera and a mobile phone. This is also happening to all digital camcorders I've tested.

A has a setting response time with values normal, fast, fastest. No matter the setting, the effect is the same.

A on the left and B on the right. You can see the flickering, although both are @60Hz

A video where you can see both monitors. A is always the left monitor.

Another video where you can see what my digital camera sees.

Another thing is that I managed to get a picture where the left monitor is completely black whilst the right one is displaying fine. This proves that the monitor is continuously flashing.

My question is: Is this normal behavior and what is causing it? Am I affected by this fast flickering? I am using this as my primary monitor and as a programmer I have to keep my eyes on it for hours.