The Monitor
Adjust the height of the monitor so that your direct line of sight hits the top of the monitor.
If you need to raise the monitor you can use anything suitable that you have on hand such as the CPU or a sturdy container
The distance to the monitor should be no closer than arm's length and as far away as possible while still being able to read clearly. Longer distances relax the eyes with the perfect distance being between 20 to 40 inches away from the eyes to the computer screen.