How Far to Sit From a Computer Screen
The Right Distance for Your Monitor
The AAO recommends sitting about 25 inches (arm's length) from your computer monitor. This distance reduces the effort your eye muscles put into focusing and converging on the screen. If you sit closer, your eyes work harder to maintain clear focus, which leads to fatigue over the course of the day.
A simple test: sit in your normal position and extend your arm straight toward the screen. Your fingertips should touch or nearly touch the monitor. If the screen is closer than arm's length, push it back or move your chair.
The AAO recommends holding smartphones and tablets at least 16 to 18 inches from your face. Holding mobile devices too close forces your focusing muscles to work harder. In children, close-range device use is associated with faster myopia (nearsightedness) progression (AAO, 2023).
If you catch yourself bringing your phone closer to read small text, increase the font size in your device settings instead. A larger font lets you hold the device at a healthy distance without straining to read.
Position the top of your monitor at or just below eye level. Your eyes should look slightly downward, about 10 to 15 degrees below horizontal, when viewing the center of the screen. This downward gaze reduces the amount of exposed eye surface, which slows tear evaporation and reduces dryness.
Laptop users face a challenge because the screen and keyboard are fixed together. Place your laptop on a stand to raise the screen to the correct height, then use a separate keyboard and mouse at desk level. This setup gives you the right gaze angle without hunching over.
Monitor Settings That Reduce Eye Strain
Your monitor should match the brightness of the room around it. A screen that is much brighter than your surroundings forces your eyes to constantly adjust between two different light levels, which increases fatigue. If your screen glows like a light source in the room, turn the brightness down. If it looks dim and gray, turn it up.
Overhead lights, windows, and desk lamps all affect room brightness throughout the day. You may need to adjust your screen brightness as natural light changes, or position your desk so that windows are to the side rather than directly behind or in front of you.
If you squint or lean forward to read, increase your screen's text size or zoom level. Most operating systems and browsers let you scale text up. Larger text lets you maintain the recommended 25-inch distance without straining to read small characters.
Set your default zoom level in your browser and email applications. These are the programs most people spend the most time reading in, and a comfortable text size in these tools makes the biggest difference in daily comfort.
Glare from windows and overhead lights reflecting off your screen forces your eyes to work through the visual noise. A matte anti-glare screen filter reduces reflections. If you wear glasses, anti-reflective lens coatings provide a similar benefit by reducing light scatter reaching your eyes.
Position your monitor so that no bright light source reflects directly off the screen. Tilting the screen slightly downward or adjusting overhead light angles can eliminate most glare without additional equipment.
The 20-20-20 Rule and Taking Breaks
Every 20 minutes, look at something at least 20 feet away for at least 20 seconds. This break relaxes the focusing muscles inside your eyes that stay contracted while you look at a nearby screen. The AAO calls this the most effective behavioral strategy for reducing screen-related eye discomfort.
Set a timer or use a reminder app to prompt you every 20 minutes. Most people lose track of time while working and go much longer than 20 minutes without a visual break.
People blink less while staring at screens. Reduced blinking lets your tear film dry out, causing irritation, burning, and blurry vision. Make a conscious effort to blink fully while working. If your eyes still feel dry, preservative-free artificial tears can restore moisture.
Your gaze angle affects dryness too. Looking slightly downward at your screen, rather than straight ahead or up, exposes less of your eye surface to the air. This reduces evaporation and helps your tears last longer between blinks.
In addition to the 20-20-20 rule, take longer breaks every one to two hours. Stand up, walk around, and let your eyes rest on distant objects. These full breaks reduce both eye fatigue and the neck and back tension that comes from sitting in one position.
No monitor setting eliminates the need for regular visual breaks. Even with perfect screen positioning and brightness, your eyes need periodic rest from close-range focus.
Setting Up Your Workspace
Your chair height should allow your feet to rest flat on the floor with your thighs parallel to the ground. Your arms should rest at desk height with elbows at about 90 degrees. This position supports a 25-inch screen distance with a natural, slightly downward gaze.
If your desk is too shallow to place the monitor at arm's length, consider a monitor arm that mounts to the back of the desk and extends the screen to the right distance.
If you use two monitors, position them so the one you use most often sits directly in front of you at arm's length. Place the second monitor to the side at the same distance and height. Avoid placing monitors at different distances, which forces your eyes to constantly refocus as you switch between screens.
For equal dual-monitor use, angle both monitors toward you so their inner edges meet directly in front of your line of sight. This reduces the amount of head turning and keeps both screens at a consistent distance.
Avoid working in complete darkness with only your screen as a light source. The high contrast between a bright screen and dark surroundings strains your eyes. Keep ambient lighting at a moderate level that matches your screen brightness.
A desk lamp with adjustable brightness can supplement room lighting for reading documents at your desk. Position the lamp so it lights your work surface without creating a reflection on the screen.
Screen Distance and Eye Health Questions
Sitting too close causes eye strain, fatigue, and dryness, but it does not cause permanent eye damage in adults. In children, prolonged close-range screen use is associated with myopia progression. Maintaining the recommended distance reduces strain for everyone.
According to the AAO (2024), blue light from computer screens has not been shown to cause eye disease or permanent damage. The AAO does not recommend blue light-blocking glasses for computer use. Proper screen distance, brightness settings, and regular breaks are more effective at reducing strain.
Dark mode reduces screen brightness and glare in low-light environments. The AAO supports dark mode for visual comfort but notes it does not prevent or treat any eye disease. Use dark mode if it feels more comfortable, but pair it with proper screen distance and breaks.
If your monitor looks like a light source in the room, it is too bright. If it looks dull and washed out, it is too dim. The screen should blend with the surrounding room brightness so your eyes move between screen and environment without a jarring adjustment.
The 20-20-20 rule addresses focusing fatigue, but your eyes and body also benefit from longer breaks every one to two hours. Stand up, walk, and look at distant objects. The 20-20-20 rule supplements, not replaces, full breaks during extended screen sessions.
Yes. Your glasses correct your focus, but your eye muscles still work harder at close distances. Maintain the 25-inch recommendation even with corrective lenses. If you wear bifocals or progressives, you may need to adjust your screen height so you look through the correct lens zone.
Protect Your Eyes During Screen Time
Set your monitor at arm's length, adjust brightness to match your room, and take regular visual breaks. Your eye doctor can recommend specific adjustments during your next exam if you experience persistent screen-related discomfort.