I switched careers and do not travel business class any more.  The zzz band is a godsend.  I don't dread full flights or having a neighbor next to me any more.  I just left my zzz band in a flight yesterday and am purchasing more because I can't fly for work without this!
I had only one red-eye flight where I could not go to sleep even without this band - but that was because the whole cabin was just very warm.
Last but not least - I have eczema/very sensitive skin and this material does not bother me at all.  I like how it even muffles a lot of sounds.
The shape blocks out light effectively.