During the day we setup our monitor to be bright, so that it show up with the stronger daylight. However, few of us will remember to turn it down at night.
That is how you get eye strain. What you really should do it turn down the brightness when you turn on the lights in the evening. Of course that is trouble and few of us will ever remember. I could also add the point that the light from our standard house lights is not the same as daylight, but you really should checkout my opinions on the different types of white light at CameraSecrets.co.uk.
However, you need not worry about this problems any more as there is a free piece of software to turn up and down the colour of your computer screen for you.
You will find it at http://stereopsis.com/flux/ . After installation, you simple let the software know where you are on the earth (my PC does not have GPS), and it will change the brightness and soften the light for you. If you need a 'true' colour for some work then there is an override from the controls that sit on the toolbar.
Available for PC, Mac and Linux!


So much of web design is creating sub-concious messages. If you don't follow the rules, you can loose a visitor because your site just 'does not feel right' One of the biggest mistakes for self made or updated web sites is bad use of colour. I am not saying that people should not update their own sites. I encourage that they do, and regularly. Whenever you add content to a site you need to check that it will Look good. you may find this colour wheel a useful way of checking the colours on your site, or for choosing a new colour mix. Of course the colour rules work for all type of medium, web and print.