Optical is dead, dead, dead.
Way back, in the mists of time immemorial, magneto-optical was used for long-term archival storage. Many regulated companies used devices like the IBM 3995 optical library (with Sony drives). The appeal was:
1. An allegedly infinite lifetime for the media.
2. Random access VS linear access for tape (faster seek times).
3. Solid state/No power required/shelf stable.
Unfortunately, MO suffered from some major flaws.
1. Horrible storage density. (last generation I worked on was 2.6Gb media).
2. Single-sided media and drives (robots that have to flip over disks are more mechanically complex).
3. Very high cost for media and drives.
4. Drive failure rates.
5. Media failure rates (according to Sony, due to excessive mounts).
6. Very low performance (If I remember correctly in the 1-10MB/s range).
Evidently, the market decided that the cons outweighed the pros, because all of the 3995's I ever supported were replaced by LTO WORM and NetApp SnapLock.
For personal long-term archival storage, nothing beats tape. Old LTO3/4 drives are ubiquitous and readily available. Media is cheap, and it is relatively fast and very dense.
Fuji estimates that tape media can last 30 years. Since this is likely longer than the interface medium (SCSI, SAS, FC) will be available it would seem adequate.
( http://www.fujifilmusa.com/shared/bin/LTO_Data_Tape_Seminar_2012.pdf )
The industry standard/common sense method to insure against individual tape failure would is to write multiple tapes with the same data.
However, I would strongly recommend that you use a timeless format like TAR or CPIO. It'd be a shame to archive your precious home-made cat food recipes and be unable to restore them because Android for Desktops v107 can't run BackupExec.
Also, with LTO, keep in mind that there are rules for which drives can read/write which gen of media.(write -1 gen, read -2 gen). Since drives are really cheap on ebay, I'd recommend getting an extra drive, seal it in an anti-static bag and put it in the safe-deposit box with your tapes.