A constant charge on the screen attracts dust. This makes the letters blur, and focussing difficult. Buy a tilt and swivel monitor base to allow different users to adjust the monitor. This makes your eyes less tired. Adjustable chairs allow you to set your chair for the most comfortable height and back support.
Visual posture is related to back posture.
Working and playing at a computer builds tension in the upper body. Your family can use the following exercises to relax their eyes and bodies. Then let your shoulders go as you breathe out saying relax at the same time. Go for a walk. Get oxygen to your body and blood to your eyes.