Using a 5D and a 1DII.
Yesterday I noticed, once again, that the info (exposure ...) is hard to read in sunny conditions.
Even when I did block the light and pushed my eye against the eyecup.
I let my friend (Nikonian) have a peek ( " Oh ya have to squeeze your eyes in order to see anything !" ) and then did check the viewfinder of his D700.
What a difference ...
Guess I have to get one of those "eye-covering" eyecups hah !?
Canon don't even make those eyecups. Bit poor for such a huge company.
The D700 sure is easy to see, even compared with my 1Ds2 and even without an eyecup which is available from Nikon.
One possibility you have is to get a Canon eye piece extender. I think it's an EP-EX1. It has a drawback that it reduces the viewfinder image size somewhat but the plus side is that you can then see everything in and around the viewfinder including the status info.
If all you want is an eyecup then there may be non-Canon options available. In the meantime you could adjust the way you hold your camera so that your right thumb offers some protection from light coming into the viewfinder from your right, or you could try using your left eye instead of your right eye but that will take some getting used to.