High definition TV screen and its effects on our brain

Nature makes us feel calm and relaxed. When we look at a scenic view such as mountains or forests, our eyes can take in the wide range of colors and shapes without much effort. 

Natural environments do not demand that we focus intensely on one particular object. 

Our attention can float freely across the landscape, reducing our mental stress and making us feel more peaceful.
Watching the same scenery on a high-definition TV feels very different. 

A screen produces bright, concentrated light and displays highly detailed images that are designed to capture our attention. 

Our eyes constantly process the brightness, the colors and the textures. The experience requires more visual effort than looking at a real landscape, especially when the watching is performed over a long time.
The amount of visual information contained in a high-definition TV scene is enormous. 

A single frame can contain millions of pixels, each carrying information about color, brightness and other visual parameters. 

With moving frames, the amount of information our visual system receives increases dramatically because objects, textures, and shadows are constantly changing. 

A manufactured high-definition scene has a very high visual bandwidth. It delivers a dense stream of information to our eyes and brain. 

Our brain, as a result, has to process a tremendous volume of visual input. This leads to mental and visual fatigue, particularly during a prolonged viewing.

People can experience headaches, fatigue, or difficulty concentrating after watching for a long time. 

A natural scenery also contains an enormous amount of information, but it is presented in a different and more natural way. 

Our eyes can freely move across the scene, choose what to focus on, and shift between nearby and distant objects. 

The information is spread across a much larger field of view rather than being concentrated into a bright rectangular object.
Our attention can therefore wander without being constricted to a small display, which make the experience way less taxing.
To mitigate these adverse effects, one should avoid watching television in a darkened room, maintain a comfortable viewing distance, and take frequent breaks.