Here are some links where you can pick and choose what you would like:
1. (Psychology dictionary & articles): (Broken Link Removed)
2. (try a dictionary for the terms you don't understand): http://www.tchain.com/otoneurology/practice/nystagmus.html
3. (pretty technical): http://www.emedicine.com/oph/byname/nystagmus-acquired.htm
4. (Wikipedia): http://en.wikipedia.org/wiki/Nystagmus
5. (Medical dictionary): http://cancerweb.ncl.ac.uk/cgi-bin/omd?labyrinthine+nystagmus
6. (Encyclopedia): http://cancerweb.ncl.ac.uk/cgi-bin/omd?labyrinthine+nystagmus
NOTE: Actually if you want something easy to understand, something less medical/technical would be better!