Saturday, December 6, 2008

Ergonomics on your computer!

Today's post is about ergonomics of your computer screen. Have you noticed that if you're on the computer for quite a while that sometimes you get a headache? That's often because of the eye strain. I'm going to review a couple common causes of eyestrain today.

If there is a window, the extra light from it can create glare (direct or indirect/reflected), which can cause eyestrain and headaches. Ideally, if you have blinds, you should shut them on bright days and on overcast days. If you don't have blinds or can't easily adjust them, you can still reduce glare by positioning your computer monitor at a 90 degree angle to the window (i.e. the window should be at your left or right).

• Try not to sit with the window directly in front of you (direct glare). It is very hard on your eyes when the computer screen is between you and the window: the pupils of your eyes should constrict (get smaller) in response to the light from outside (to let less light into your eye). However, the pupils dilate (get wider) in order to read the monitor - your eyes will to let more light in than they want.
• Also, try not to position the window behind you. The computer screen, even one with an anti-glare screen, can easily reflect light (indirect/reflected glare), which is bounced back into your eyes. The light reflecting off your computer screen should cause your pupils to constrict, but the pupils will actually dilate in order to read the monitor. Again, your eyes will let more light in than your eyes want.
• This biological response of a pupil dilating in spite of the light will let more light into your eyes than your eyes like, which could cause eye strain. Click here to read more about how your eyes respond to light (dilation / constriction responses).

And you should learn the 20/20/20 rule. For every 20 minutes of computer work or reading on the computer screen, take a 20 second break in which you look at an object at least 20 feet away. This gives your little eye muscles a break from reading the screen. Think of it as an eye rest.

Now that you know where in the room you should position your monitor, and how to take eye breaks, I have a question for you.

Which of the following screen / font colour combinations is the best (least strenuous) for your eyes?
a. A dark background with bright colours (such as green or red)
b. A dark background with light colours (such as white, cream or yellow)
c. A white background with bright colours (such as green or red)
d. A white background with dark colours (such as black, brown or blue)

I will post the answer in the comments tomorrow. If you're not afraid, feel free to post your answer (or guess!) in the comments box. Check back tomorrow to find out the answer.


Krista said...

The correct answer is d: a white (or very light) background with very dark colours is ideal: it is the easiest on your eyes, and thus causes the least eye strain.

A dark background with light or bright colours can strain your eyes. A white background with bright colours is better, but could still strain your eyes.

EliandMe said...

Yay, I got it right! I learnt something new from reading your blog this weekend. And now I'm going to go and complain to my manager about my chair.

Krista said...

Approach it as a business case for your productivity! :)