Topic summary
Optical media
Extracted from the Wikipedia article Optical disc.
Surface error scanning
Optical media can predictively be scanned for errors and media deterioration well before any data becomes unreadable. Optical formats include some redundancy for error correction, which works until the amount of error exceeds a threshold. A higher rate of errors may indicate deteriorating or low-quality media, physical damage, an unclean surface or media written using a defective optical drive.