Small black dot near top left corner of screen on CRT monitor

hi,I have a Likom Viewmate LP995 19 inch CRT monitor which is like 4-5 years old, a couple weeks ago a small dot maybe the size of 1 or 2 pixels (yes it's a tiny black dot) appeared. The dot is barely noticiable in fs2004 thankfully. What is this dot and why does this happen? Is it a sign of my monitor going south?Andrew