Employees who work all day at a computer are at risk for eyestrain. To help your workers protect themselves, we recommend that they follow these basic precautions.
- Look away from the monitor for 30 seconds, every 15 or 20 minutes. Look at or scan things at least 20 feet away to allow your eyes to focus in a rest position.
- Reposition the monitor 20” to 26” from your eyes (roughly the distance from your eyes to the end of your index finger with arm outstretched). Otherwise, you’ll be forced to sit or lean too close to the screen, or sit too far away. If your eyeglass prescription doesn’t allow clear vision at the 20” to 26” range, get it adjusted.
- Reset monitor height so that the top edge is even with your view when looking straight ahead. Then tilt the screen upward so that you’re not looking at the image at an angle. The optimal screen position is 10 to 20 degrees below eye level.
- Reset the monitor screen resolution, the Internet browser text size, and the zoom and font default in the operating system and in software applications so that text is easy to read. Start with a screen resolution of 800×600 for older CRT monitors and 1024×768 or higher for LCD (flat screen) monitors. Set the monitor refresh rate at or above 75 hertz (Hz) on older CRT models. Refresh rate is irrelevant for LCD monitors and is factory set, usually 60 Hz.
- Blink often (put a sticky note on your monitor!). The average blink rate is 22 times per minute. The rate goes down to seven per minute when looking at a monitor – which causes the eye lens to dry out. If you can’t get into the habit of blinking more often, use an eye moistener (saline solution).
- Relax your eye muscles. Put the palm of your hands over your eyes for a minute or so, once every half hour. This warms the muscles around the eyes, relaxing them.
- Minimize glare. Make sure the background light level around the monitor is about the same as the screen light level. Minimize direct sunlight or bright lights in front of the monitor or directly behind it.
- Adjust the contrast and brightness to levels you use when reading a book comfortably. A bright screen causes eyestrain.
- Use a paper holder to hold documents. Put the document at the same level as the monitor, or attach it to the monitor. This prevents repetitive neck and eye movement from paper to screen.