I have never heard of the term "cybersickness" before. I googled it, and it seems to be what we commonly refer to as "motion sickness". It just emphasizes that this is not caused by physical motion, but by motion seen on a screen. So it's just a more formal/correct term to what people have been using for years in common language as "motion sickness" (especially when it comes to gaming).
I doubt you get motion sickness from a text processing program, unless you truly keep scrolling up and down a lot more than the average user. You typically get it from 3D games or 2D sidecrolling games.
You probably get symptoms from looking at static screen content. Please clarify if that assumption is wrong.
I noticed that when going back to displays that caused small symptoms but once seemed usable, the symptoms seem to be much stronger than I remember. It seems there is a certain degree of adaption involved that may fade within weeks/months of not being exposed to the display anymore.