Blinkers (horse tack)

The stays join together in the middle, go between the horse's ears, and are attached by a buckle to the crownpiece of the bridle.

Many racehorse trainers believe that blinkers keep horses focused on what is in front, encouraging them to pay attention to the race rather than to distractions such as crowds.

[3]: 20 Visor blinkers have a peep hole cut in the back of the cup.

[6] A blinder is a name used in the United Kingdom for a bag or cloth blindfold put over the head of a difficult horse while it is being handled—for example when being loaded into starting gates or being mounted.

[3]: 19 Both "blinker" and "blinder" are also used metaphorically to refer to people with an overly narrow focus or inability to see the larger picture.