How high should your monitor be? Eye level, tilt and two screens

The top of your monitor should be at or slightly below eye level when you sit back in your chair, so that you look a little down to the middle of the screen. The American Optometric Association suggests the center of the screen sit about 15 to 20 degrees below eye level, which is roughly 4 or 5 inches lower, with the screen 20 to 28 inches (about 50 to 70 centimeters) from your eyes.

That holds for most people at a single display. It shifts a little for very large screens, for two monitors, for a laptop beside a display, and for anyone who reads through the bottom of bifocal or progressive lenses, and each of those gets its own section below.

Why slightly below eye level

There are two reasons, one for your eyes and one for your neck.

Your eyes are most comfortable looking slightly down. A lowered gaze also lowers your upper eyelids, so less of the eye's surface is exposed to the air, which can help with the dry, gritty feeling of a long screen day.

Your neck prefers your head balanced over your shoulders. When the screen sits a little below eye level, your eyes do the small amount of looking down and your head can stay level. Move the screen away from that and your head follows it.

• Too high. Your chin lifts and the back of your neck tightens. This is common with a big display on a tall stand, or a monitor on a riser it doesn't need.
• Too low. Your head drops forward and your shoulders round. This is the classic laptop posture, and it is the more common mistake of the two.

"Slightly below" is a range, not a point. If the top of the screen is anywhere from level with your eyes to a little under, and you can read the whole screen without tipping your head up or nodding down, it is in the right place.

How to find your eye level

You need your usual chair and about a minute.

1. Sit the way you work. Back against the chair, feet flat, hands on the keyboard. Not perched on the front of the seat, and not slumped. If you change chairs later, do this again.
2. Find your natural eye line. Close your eyes for a few seconds and let your neck relax, then open them and look straight ahead without moving your head. Where your gaze lands is your eye line.
3. Compare it with the screen. Look at the top edge of the picture, not the bezel or the stand. If your gaze lands on that edge or just above it, the height is right. If it lands on the wall above the screen, the screen is too low. If it lands partway down into the picture, the screen is too high.
4. Check the middle. Read a line of text in the center of the screen. Your eyes should drop to it without your chin dropping with them.

How to raise or lower a monitor

Most fixes need nothing new.

• Use the stand you have. Many monitor stands slide up and down, sometimes with a firm push and sometimes with a release button at the back. Apple has offered the Studio Display with a choice of a tilt-only stand, a tilt and height adjustable stand, or a VESA mount adapter, so check which one yours has before stacking books under it.
• Lift it on something solid. If the stand doesn't go high enough, put the whole display on a ream of paper, a few hardback books, a sturdy box or a monitor riser. Keep it flat and stable, and check it doesn't rock when you bump the desk.
• Lift an iMac the same way. Most iMac stands tilt but don't go up or down, so a riser is the usual way to raise one.
• Use a monitor arm. An arm clamps to the desk and holds the display by the mounting holes on its back, if it has them. It lets you set height, distance and tilt separately and frees the desk underneath. Check the arm is rated for your display's weight.
• When it's too high and won't come down, take it off its stand and use an arm, or raise your chair and put a footrest under your feet. Raising the chair changes your desk height too, so check your elbows still meet the keyboard comfortably afterwards.
• For a MacBook, the only way to lift the screen without lifting the keyboard is a stand with an external keyboard and trackpad in front of it. Do you need a laptop stand goes through when that is worth it.

Tilt, distance and big screens

Height is one of three settings that work together.

• Tilt the top back slightly, so the screen faces your eyes rather than your chest. With the screen dark, look for reflections of lamps or windows and adjust the tilt until they're gone.
• Set the distance. Sit back and stretch an arm toward the screen. Your fingertips should reach it or come close. How far your screen should be from your eyes has the details.
• Make text bigger rather than moving closer. If you lean in to read, go to System Settings > Displays and choose a scaled resolution one step toward Larger Text, or press Command and the plus key in the app you're using.

Larger displays need more distance, not a different height rule. Put the top edge at eye level or a little under, then push the screen back until you can see the corners without turning your head much. If you catch yourself tipping your chin up to read the menu bar, the screen is too high or too close. With a wide or curved display, center it on your body and keep the same height rule; the curve is there so the edges stay at a similar distance from your eyes.

How high should two monitors be?

Two screens are easiest on the neck when they behave like one.

• Line up the top edges, both at or a little under eye level, so your eyes move across rather than up and down.
• Keep them at a similar distance, so your eyes don't refocus every time you switch.
• Put the one you use most straight in front of you. If you use both about equally, put the seam between them in front of your nose and angle both in a little.
• Raise a laptop to match. A MacBook beside a display belongs on a stand, with its top edge roughly level with the display's. Left flat on the desk, it makes every glance at it a nod.
• Be wary of stacking. A second display above the first means looking up. Keep the screen you use most on the bottom row, and use the upper one only for things you glance at.

Then tell your Mac where the screens are. In System Settings > Displays, recent versions of macOS let you drag the displays in the arrangement to match the desk (click Arrange first if your version shows that button). If the laptop sits lower than the display, drag it lower in the arrangement too, so the pointer crosses between screens where your eyes expect it. MacBook and external display setups goes further into which screen should lead.

What if you wear bifocals or progressive lenses?

The usual rule assumes you look straight through your glasses. With bifocals or progressives, you read through the lower part of the lens, so a screen at standard height makes you tip your head back to see it clearly. Over a day, that is hard on the back of the neck.

• Lower the screen. Start a little below the usual height and keep going until you can read the whole screen with your head level. For some people that means the display sits as low as its stand allows.
• Tilt it back a bit more than you otherwise would, so it still faces the part of the lens you read through.
• Ask about screen glasses. An optometrist can prescribe lenses set for the distance of a computer screen, sometimes called computer or office lenses. Measure how far your screen is from your eyes before the appointment and take the number with you.

If you still find yourself craning after all this, the prescription may be the problem rather than the monitor, which is a question for an optometrist.

A check in the afternoon

A monitor rarely moves on its own. You do. Over a long afternoon you slide forward in the chair, your eye line drops, and a screen that was right at nine is a little high by four. Laptops drift more, because they end up back on the desk or on your knees.

Notchpals, the Mac app with reminder characters living in the notch, saves one visit a day for this, timed for the afternoon when the slide has had a few hours to happen. The Posture character in your crew drops down for Screen distance. Matsu, a bonsai with three centuries of patience, puts it like this:

MatsuRaise the screen to your eyes. I grew toward the light. It did not bend to me.

Take it as your cue to redo the eye line check above: sit back, look straight ahead, see where your gaze lands. If the fix needs a book under the stand and you're mid-task, Later gives you twenty minutes before Matsu asks again.

If your eyes or neck still ache once the screen is in the right place, see an optometrist or a physiotherapist. Moving a monitor won't fix an out-of-date prescription or a neck problem.