I'm not sure if this has been posted before, if so apologies.
This two part documentary is well worth watching and is available on DVD.
YouTube - Dead Tired - The documentary
It is now possible to lose your drivers license in many countries if you are diagnosed with a sleeping disorder, perhaps somebody could post some information on how this could affect an aviation medical. I know many many pilots that exist on very little sleep due to a combination of rostering, jet-lag, poor quality hotels, poor eating habits etc. I even know of a few with diagnosed sleep disorders.
This program even showed a trucking company that was about to have its insurance revoked due to its high accident rate as a result of driver sleep problems.
How many accidents/incidents could be attributed to these issues amongst pilots and engineers?