The Science of Racing: Vision and Blinkers

August 22nd, 2022

Your favorite Thoroughbred can be run all day long, their potential deep. The talent and heart are there, if only you could get them to run straight or navigate turns more efficiently. How do you make that happen?

One way to mitigate those kinds of bad habits is to change how they see the racetrack. Understanding how they see and what piece of equipment might work best becomes key to that decision as they prepare for their next race.

This month, the Science of Racing looks at a horse’s vision and how changing the way they see the world around them can affect performance.

How Equine Vision Works

 Sporting the largest eyes of any land mammal, a horse’s eyes are positioned laterally, on either side of their skull rather than set in front as a human’s are. This allows horses to have 350-degree vision, while humans are limited about 135 to 180 degrees. Each eye, which functions independent of the other, has a field of vision that spans 285 degrees, while both eyes together have about 65 degrees of binocular vision. Because of this limited range of binocular vision, horses have limited depth perception and cannot judge distance as well as humans can.

This wide visual range makes sense when we consider that horses are prey animals; in the wild, their eyes would constantly scan their environment looking for predators. The position of their eyes leaves them with only two blind spots, directly behind and directly in front. Their forward blind spot, which stretches from eye level to below the nose and about six feet out, is due to the position of their eyes and where the planes of vision overlap. That means, if a horse decides to jump an obstacle, they cannot see that obstacle immediately before they start to jump.

Understanding the width and depth of a horse’s vision can help you understand why they behave the way they do while racing. If a horse spooks or shies at an object or a shadow or if they tend to lose focus during a race, a trainer will look for the right piece of equipment that can cut down on or prevent those behaviors.

Tools of the Trade

Whether they are racing down the stretch on dirt or turf, sprinting or stretching out over a distance, racehorses may need some help focusing on the task at hand. To accomplish this, trainers can add blinkers, shadow rolls, or cheek pieces to their horse’s tack to correct whatever issue might be compromising performance.

The most common tool you might see on race day are blinkers, a hood that goes around a horse’s head with cups that cover the eyes. Typically made of nylon, the attached plastic cups are different sizes depending on the trainer’s assessment of the horse’s need, ranging from the barely-there cheater cups to the full cups. The goal is to narrow a horse’s vision to improve their focus during their races.

Extension cup blinkers cover one eye, limiting vision to only one side of the horse’s head. Full cup blinkers restrict horses to only what is in front of them, with small holes toward the back of the cup so that horses can see competition approaching from their rear. Both semi-cup and French cup blinkers are less restrictive than the full cup but cover enough to keep a horse looking forward or to the side but not to the rear. A cheater cup blinker has a narrow cup, limiting vision the least but just enough to remind the horse to focus on the task at hand.

If blinkers are not the right option, a trainer may add a shadow roll instead. Shadow rolls are a piece of wool or other synthetic material wrapped around the nose band of a horse’s bridle. Whereas blinkers will cover the eyes on either side of a horse’s head, restricting their view of the racetrack, the shadow roll partially obscures what is in front of the horse, making them lower their head so that they will shift their focus forward. This is especially helpful if a horse tends to run with a higher head carriage or if a horse tends to spook or shy from objects like shadows.

Cheek pieces are made from similar material as shadow rolls, except that the rolls are attached to the cheek straps of a horse’s bridle, running from ears to mouth. Less restrictive than blinkers, cheek pieces do limit a horse’s rear vision so that they concentrate on what is in front or to the side. If a horse does not like blinkers but still needs something, cheek pieces can fill that need.

Regardless of whether a trainer chooses blinkers or cheek pieces, the most important aspect of adding a piece of equipment is to acclimate the horse to this new part of their routine. Horses will school and work out with their tack on, helping them settle into the new arrangement.

Whirlaway wins the 1941 Kentucky Derby (Courtesy of the Kentucky Derby/Churchill Downs)

Famously Blinkered

The history of horse racing has its share of great horses that have worn blinkers. Whirlaway famously wore a one-eyed set, trainer Ben Jones outfitting the Calumet colt with a hood that included a cup over his right eye. Since the colt had a habit of bearing out on the far turn, covering that eye meant that he could not see the outside rail and instead could see only to his inside. The strategy worked: Whirlaway went on to a Hall of Fame career, including a Triple Crown in 1941.

Secretariat also ran in blinkers, trainer Lucien Lauren using them to keep him focused on running and avoid ducking in toward the rail. Gallant Fox wore blinkers as well, but his cups were gradually cut down as the Triple Crown winner progressed through his two seasons on the racetrack. Trainer “Sunny Jim” Fitzsimmons could have simply taken them off, but he felt it would be bad luck to remove them.

Things to Consider

Understanding how a horse’s vision works and why a trainer will choose a particular set of blinkers or other addition to their tack can help you decide about your wagering options for a horse’s next start. That change could prompt the horse to perform better or maybe sulk and refuse to run in their next start. So, the next time you are at the races, make sure you check the past performances for a note about blinkers on or off. A change of equipment can be an important piece of information as you consider how to bet the next race.