Why do carriage horses have thei..

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And how do they even go around so fast.Do they have complete trust in the driver?Answers: samurai is rightIt is NOT usually to prevent the horse from .. 

FWIW, if you're into driving horses, a driving bridle without blinders is a special order. The places that make harness equipment, including driving bridles, just make them with blinders because that's the way they've always been made. I didn't particularly like driving my horse with a blind bridle, because I had to drive on bridle paths that were rather narrow and fenced on both sides. I wanted my horse to be able to see the fence. So I just swapped out his driving bridle for the English bridle I rode him with, replaced the Eggbutt French snaffle I rode him with with the driving snaffle, clipped the driving reins onto it and away we went. No problems. It really is not more difficult to drive a horse with an open bridle than one with a blind bridle.

In showing driving horses, the "turnout" or visual impression of the horse and vehicle are judged, and in general because of the tradition of driving horses with blind bridles, a horse or team that is shown in open bridle is going to look strange compared to the other competitors. For this reason most competitors are going to be loath to show in open bridles.

With regards to the horses having complete trust in the driver, for any horse to compete successfully in any event, there has to be a relationship of trust. This involves hours and hours and hours and hours of training and work outside the showring or competition course, with horse and rider/driver learning about each other and learning how to communicate and "read" the various aids and cues. People who compete in driving events will tell you that while a well-trained horse or team and an expert driver can go in "cold," without knowing each other, and manage to complete the course, it really takes getting to know the horse or horses in the team and the team learning about the driver to make a winning competition.