I came across an interesting video, showing how to sit correctly in front of a computer.
Some people bend their back, while sitting in front of their computers. Others, sit too far away from the screen, which is not healthy for the eyes. Some, have the screen placed too high or too low. In other cases, there is too much light falling on the screen, making it difficult to read.
All this can be tiring for the eyes, the hands and the back. This video, without words, and only through animations, shows how to sit correctly.