1) The recommendation to "Always have lights on in the room when using the computer. There should not be a big contrast between the lighting on the screen and in the area surrounding it." may not be beneficial when using a computer monitor. Extra lighting does not allow for an adequate visual contrast. The increased room or window ambient light can create increased eye strain. About 30fc is the recommended room lighting for computer monitor visualization. 2) "Make sure children learn to sit an arm's length away from the screen (12 to 14 inches)." The recommendation is at least 18-30 inches; although a minimum of 24" is preferred. The term "arm's length" refers to an adult arm. This is very challenging when laptops are utilized. We frequently recommend docking them so that users can obtain an improved posture.
http://www.permanente.net/homepage/kaiser/video/ergonomics/index.html