A screen saver is a software program that turns itself on when a computer has been inactive for a set length of time. It manifests itself as a moving image on the screen, sometimes accompanied by sound. The idea is to stop the screen being permanently damaged by an image that doesn't change. If a computer screen shows the same image for long enough, the image will be permanently etched into the monitor.

The stream of electrons from the cathode ray tube at the back of conventional monitors can damage the fluorescent material that produces the colours we see. Screen savers are particularly useful for computers that are left on for long periods of time, such as those in libraries, schools, or offices.

Types of Screen Saver

There are many kinds of screen saver. There are some that are pre-installed on many computers, which just need to be activated, after selecting your choice of image. Many screen savers can be downloaded off the Internet, which provides a massive choice. Screen savers are rarely intended to save energy.

Some typical screen savers:

• Bouncing balls/text/animation

• Mazes

• Games¹

• Programs - for example, the SETI screen saver

• Energy savers that put the screen on stand-by

• Information - favoured by schools and offices

Problems

Screen savers have a propensity for becoming irritating and distracting. This is one of the reasons for the huge number of screen savers around. Anyone who has had to share a computer with a screen saver will understand the urge to follow its every move or alternatively throw something at the screen. This tends to stop you from getting much work done and the last thing you need is another excuse.

Another problem with screen savers is that they sometimes turn themselves on when you are in the middle of reading or observing something; such as when you are halfway down the first page of your company report and the screen turns itself off to save energy. It takes another ten seconds for the screen to warm up again, breaking your concentration. This may ruin your concentration for the rest of the day, because you may find yourself constantly fidgeting with the mouse to make sure that the screen won't turn itself off again.

A final problem is the fact that screen savers get repetitive very quickly. They can only hold your interest for a short period of time. The reason behind this is that they are designed to take up as little space as possible on a computer, and the program is looped a few times to make it continuous. In their defence though, it must be said that they were never intended to be watched for more than a few moments at a time and if there is nothing more fulfilling in your life than your screen saver, it's time to make some serious changes.