The blinkers on a race horse serve a purpose, preventing the animal from distraction by its neighbours and focusing its attention on the jumps and, ultimately, the finishing line.
Over the years, trainers have determined that this is the best way to win races: strap on the blinkers and your horse remains single-minded.
Now and then we all have tasks which demand our complete concentration, and when this is the case it can be helpful to do the human equivalent of donning blinkers. Turn the TV off, switch your phone to silent, ask others not to disturb you.
If you don't really need such laser-like focus, however, there's much to be said for doing just the opposite, paying as much attention as possible to the world around you.
If you were to sketch a down-hearted person you'd probably draw him with a hanging head. Chin to chest, his eyes would be fixed on the floor. When your mood is low, your perspectives become shortened, and your attention becomes limited. The cause is having the blues, the effect is temporary blindness to the world around you.
We can hack these dynamics, however, running the machine in reverse so that the cause becomes looking intently around us, and the resultant effect is that our mood is lifted, even if only a little.
So look around. Properly. Almost certainly there will be a lot to see, and pretty certainly you'll feel the benefits of paying proper attention, even if it's just that you avoid walking into lamp-posts.