Ah yes, the old sunglasses trick. Mostly employed to hide the bloodshot eyes. Rather useful for hangovers too..
I recall a flight from LGW to Accra many moons ago, when some colleagues and I managed to consume a larger quantity of the inflight bar than would nowadays be permitted. We all suffered from severe "jet lag" the following morning and had to meet a client for a difficult meeting at 10am. Sitting beside my boss, with line of sight to his eyeballs, I could see why he wore his Raybans through the whole meeting...
