Why do I have a strange eye problem?!

When I was younger I used to get a strange eye problem, it seemed as though everything closed in and that I couldn't distinguish distance. I spoke to a doctor who said the problem was that my eyes were tired or strained and I did notice that the problem came on if i read something while i was tired. However I did not get the problem for a few years after that but recently I experienced it again while I had a temperature and slight fever. I have been short sighted for a few years and sometimes wear glasses or contact lenses. Please could you help me with an explanation of this problem and any other information about it e.g a name, or diagnosis etc.