What exactly are "blinkers"?

Question

What exactly are "blinkers"?

Answer 1

They look like a fly mask, with circles cut out over the eye section. Stiff plastic cups in the mask keep the horse looking forward, where their business is, instead of paying attention to a horse running alongside, or a horse coming up from behind.

Seabiscuit wore them:

http://www.pbs.org/wgbh/amex/seabiscuit/...

Answer 2

They block the horse's view so they can focus more on what's in front of them rather than what's on the side of them!!!!

Answer 3

They are directionals.  When you want to turn left you put the lever on the left side of the steering wheel down!  Put it up to show you are going to turn right!

Okay?

Answer 4

Well, in horse circles, the blinding 'flaps' placed beside a horse's eyes to block peripheral distractions....