4. Upgrade your display.
If you have not already done so, replace your old tube-style monitor (called a cathode ray tube or CRT) with a flat-panel liquid crystal display (LCD), like those on laptop computers.
LCD screens are easier on the eyes and usually have an anti-reflective surface. Old-fashioned CRT screens can cause a noticeable "flicker" of images, which is a major cause of computer eye strain. Even if this flicker is imperceptible, it still can contribute to eye strain and fatigue during computer work.
Complications due to flicker are even more likely if the refresh rate of the monitor is less than 75 hertz (Hz). If you must use a CRT at work, adjust the display settings to the highest possible refresh rate.
When choosing a new flat panel display, select a screen with the highest resolution possible. Resolution is related to the "dot pitch" of the display. Generally, displays with a lower dot pitch have sharper images. Choose a display with a dot pitch of .28 mm or smaller.
Flicker is not an issue with LCD screens, since the brightness of pixels on the display are controlled by a "backlight" that typically operates at 200 Hz.
If you see a lower refresh rate (e.g. 60 Hz) noted on an LCD screen, don't worry — this refers to how often a new image is received from the video card, not how often the pixel brightness of the display is updated, and this function typically is not associated with eye strain.
Finally, choose a relatively large display. For a desktop computer, select a display that has a diagonal screen size of at least 19 inches.