Where is your monitor located? Next to a window? Under a bright light?
Did you know bright fluorescent lighting can cause eyestrain, particularly if it creates a glare on your computer monitor? Conversely, having too little light also can result in eyestrain when working with paper documents.
Finding the right balance of light is an important part of an effective workstation. Unfortunately it’s a topic that is not often discussed because employers struggle with where to start. The following questions should give you some direction.
Do you have a window behind your computer monitor? If so, does the sun come peering in at certain times of the day? Start by closing the blinds or arrange the environment so any direct sunlight is either filtered or is not directly aimed at the monitor. If you are one of those people who enjoys looking outside while working at your computer, you will need to filter the light directly behind your monitor (this may require covering the entire window at certain times of the day).
Why do your eyes become strained? There are approximately 120 million rods and 6 to 7 million cones in your eyes. Rods perceive shape and dimension, and are not sensitive to color. Rods help us adapt in dark settings and are more than a thousand times more sensitive than cones. They allow our peripheral vision, depth perception and motion sensing. For example, when looking at stars in the night sky, it is your rods that see the star. Why? Because it is the motion of the star that is being picked up by your peripheral vision.
Your cones distinguish color and can adapt more quickly to changing light levels (e.g., going outside to a sunny day after taking in an afternoon matinee). The cones are designed to take in 64 percent red and 34 percent green spectrum and approximately 2 percent of the blue spectrum. The purpose of the cones is to provide high resolution vision.
What does this mean for me? For those of you who spend a lot of time on your computer, staring at your screen for a long period of time can give your eyes that tired feeling. There’s a reason for this.
The display screen on your computer illuminates bright lights. The contrast from this, along with lighting around you, causes images on your computer to fade and your eyes have to work harder to see your work. The combination often leads to headaches, too. 
What do I do?
- When looking at your computer monitor, make sure you are not directly under a white light (e.g., desk lamp, fluorescent fixture).
- Block unfiltered sunlight from shining directly at, above, behind and to the side of your monitor.
- Make sure the desktop lights are not directly in front of you or at or above your line of sight (at or above the top of your monitor).
Organizing your work surface and environment, utilizing these simple tips, will help you optimize your eyes’ ability to utilize their components most efficiently, and mitigate excess strain. By taking simple steps to decrease eyestrain you ensure employees are able to maintain productivity and avoid more serious conditions.
- Roy Matheson & Associates, Copyright 2004-2010 Office Ergonomics.
- http://www.osha.gov/SLTC/etools/computerworkstations/wkstation_enviro.html. Accessed July 19, 2011.