Difference in Class 1 & 2 Medicals
 

I am unable to find the answer to this one in any of the forums, apologies if it's already been answered before.
I want to know what the difference between a class 1 & 2 medical is? More specifically the South African CAA but any answer will do just to give me a flavour I suppose.
Reason for this is I have a class 2 for my PPL and have permanent tinnittus :( but still pass my class 2 medical. (according to ME I have it quite bad, a fact that I'm very much aware of!, but he's happy that it's not getting worse.)
Will this be a problem if I decide to go for a CPL and therefore need a class 1?
Many Thanks