If your monitor is blur, you should
a) Have your eyes checked.
b) Work for only 59 minutes and 59 seconds every day
c) Change your monitor.
Seriously, though, if your monitor is quite old and is starting to have this problem, it probably means that the cathode-ray tube is about to burn out. If this is the case, then you might as well buy a new monitor, as the repairs alone would probably cost you as much as getting a new one.
If your monitor is new, take it back to the people who sold it to you, tell them you have a faulty monitor and get a replacement.