Data degradation is common on CDs stormed in homes, this is due to constant attack by signals in your home, such as microwaves and cell-phone and magnetic interference.
Your best bet is to actually run the disk through a data recovery programme and see if you can get anything from it, if you cant then you would need to send it off to specialist labs to try and recover data (though that isn't very cheap so you would need to think if the data is worth it)
If you want to try it your self, I tend to use:
http://www.recovermyfiles.com/ you can download that and install it to your computer, and run it on your cd/dvd drive with your CDR to see if it can find anything to recover, and you can do that usually without paying for the program, but once its finished and its found data for you, you can pay for the program license so you can recover your files, lots of info on it all on the website.
If that does not work and you think the data is worth it:
http://www.vensys.co.uk/data-recovery/ and they have a no-data no charge policy.
But usually when i recover files for people "recover my files" program works a charm!
Hope this helps