I had a similar problem with my PS3 not reading bluray or PS3 games. I ended up opening my system and then the drive and disassembled the laser piece and cleaned both lenses.. since i did that it's been reading flawlessly.
I'm not an expert but there's plenty of videos on youtube and such to make taking your system apart less intimidating if that's an issue for you. If you're still not comfortable taking it apart though then by all means, don't. Just sharing what solved my problem in hopes that it helps somehow.