1- The larger your screen, the further away you need to sit.
2- Recommended distance from the screen is about 50-70 cm.
3- Your screen should be in front of your face.
4- If you use 2 screens, you have 2 options:
a. Place the main one (used over 70% of the time) in front of you, and the secondary screen next to it, turned in towards you.
b. When using both screens at the same time and the same amount of time (50%-50%), place both of them together so you sit in front of the connected edges of screens.
5- As the screen sits below eye level - tilt the screen slightly upwards toward your face at 15°. This helps the neck stay at neutral position while the eyes are looking downward, without stress and effort.
6- If you wear bifocals, lower the monitor so that the monitor sits as low as possible. This will help you prevent the need to tilt the head back (to look down through the glasses), causing tension in the neck and shoulders.
7- Consider getting a dedicated pair of glasses for computer work.
8- Adjust level of brightness and contrast so you can see clearly and without unnecessary strain. If you need the text larger - learn how to adjust the font and zoom in and out, without decreasing the resolution.
9- Use a font which is larger (by 3 sizes) than the smallest font you can actually see. For example, if you can see font 9, use 12.
10- Adjust the amount of blue light so it decreases in the afternoon and evening. This will help you get your body ready for night sleep.