Supposed to. If you do any backups to DVD/BD and still want to get your data back in 5 or 10 years, though, you'd be well advised to do some sort of FEC - burn multiple copies of each disc, generate a bunch of PAR2, whatever.

(You might want to do that for backups on hard drives too. Yeah, maybe the hard drive firmware is supposedly taking care of any errors below the block level and you're not too worried about bitflips, but that just means you'll lose entire blocks and files when you lose something.)