Preventing Visual Discomfort
Computer workstations present complex visual needs. Challenges can include uneven lighting, reflections and glare, and prolonged use of the eyes. Here are some guidelines to follow to reduce visual discomfort:
Keep lighting levels as even as possible.
To determine problem areas, shield bright sources from your view with your hand or a file. If you feel relief, eliminate the bright source.
- Use indirect lighting sources and task lights.
- Use low-glare bulbs or cover bright bulbs with filters.
- Adjust light levels by turning off light banks or using adjustable light switches.
- Avoid sitting so that overhead lights are within your visual field.
- Wear a visor to shield your eyes from bright overhead lights.
- Reduce light from windows with shades or room partitions.
- Sit at right angles and at least 3 feet from windows.
- Avoid glossy, reflective wall paint or reflective light-colored work surfaces.
- If you can see your own reflection or the reflection of windows and lights in your monitor screen, you have a glare problem.
- Use a monitor visor to reduce glare from overhead lighting sources.
- Consider using a good quality glare guard. Use a polarized filter if you sit near a window.
- Adjust the monitor tilt to avoid reflections from windows and ceiling fixtures.
- Adjust screen/character background. Use dark characters on a light background. White characters on a blue background can provide positive contrast while limiting glare often seen on a white background.
Select a high quality monitor
- Size is not the only consideration.
- Select a monitor large enough for the work you complete. The size of the text should be three times the size of the smallest text you can read. If you work with spreadsheets, you will need a larger screen to view your work.
- If you don't need a color monitor, consider a monochrome monitor with higher screen resolution.
- Adjust contrast level to maximize character definition.
- Select a color monitor with dot pitch less than.28mm.
- Use refresh rates above the standard 60 Hz default setting to reduce flicker. A minimum of 70 hertz is recommended.
- Select a screen with good screen resolution (more pixels). Make sure you don't compromise resolution for a lower refresh rate. Both are important.
- Adjust the screen brightness to match the general brightness of the room.
Set up your monitor to reduce eye and neck strain
- Position the center of the screen 10-20 degrees below your straight-ahead gaze. You should be able to look at your screen without tilting your head.
- The closer an object, the harder your eyes work to focus. Place the screen as far away as possible, provided you can read it easily. Adjust font size if necessary.
- Keep the screen and source documents at about the same distance away from you to avoid constant re-focusing while working.
Use good work habits.
- Eyestrain can result from dry eyes. Blinking helps lubricate your eyes. Post a "Blink" post-it note on your monitor to remind you to blink while working.
- Follow the "20-20-20 rule". Every 20 minutes, look 20 feet away for 20 seconds to rest your eyes.