The Learning Never Stops
Minnie brought something new to my attention when she did a massive shy the week before last (see previous blog post Awareness vs Adrenaline). At first I thought it could be dietary, and that she could be lacking a nutrient in her feed. I researched the quality of our local hay and found that it is deficient in Magnesium and Copper. I ordered a mineral mix that is specifically formulated for Arizona hay and have had her on it for a couple weeks. I have noticed a change her demeanor, she is generally calmer.
After the big shy, her confidence was rattled when I took her off the ranch. When we rode with other horses she was walking much faster than her usual relaxed gait, so I knew she had a nervousness that wasn't there before. I pulled in her focus and spend a few rides not leaving the ranch. She was very nervous at first on the short trails that she has been on dozens of times. Each time she put her head up and went into a freeze and spin position we worked though it by pulling her focus back in and trotting some circles. Over the course of three rides she was back to being relaxed on the ranch trails.
Then something really interesting happened. We were quietly walking with a friend who was riding her horse about 20 feet behind us. Her horse stopped to poop, so we stopped and turned around on the trail to wait. Minnie was facing her horse who was directly in front of her. When he started to move, she acted as though she hadn’t seen him, she threw her head up into the freeze position and started backing up to go into a spin and bolt. I quickly turned her head to the side so that she was looking at him with one eye and moved her toward him and she immediately stopped shying. Hmmm. For the rest of the ride she was quiet.
That made me wonder about her eyesight and what she was seeing. So I started doing some research about how horses see. I knew about the blind spot in their vision behind them but I had never really thought much about how they see in front of them. During my Googling the subject I found some fascinating research that is fairly recent.
Horses have a blind spot in front of them, which of course makes sense because their eyes are on the sides of their head. So when a horses is “on the bit” in dressage or they are traveling with their head low, they literally can’t see where they are going. The size and the shape of the blind spot varies depending on how the horses eyes are placed on their head. With my horse Minnie, her eyes are placed well to the sides of her head and the size of her eyeballs are average, so to see directly in front of her she has to raise her nose to look through the bottom of her eyes. The vision in the bottom of a horse’s eye is near sighted and three dimensional - so they can see what they are eating very well. When I am standing directly in front of her she raised her head to look down her nose at me so she can see me.
As Minnie has clearly shown me twice now, her blind spot in front of her is roughly 20 feet in front of her when her head is down. As an object enters the horse’s blind spot directly in front of them it becomes blurry, then disappears. If the horse raises their head to look down their nose and get a better view with both eyes (their binocular vision), the object appears 3 dimensional - like human eyesight.
if there is an object they are viewing only with one eye, it is in their monocular vision. In their one eye view, the image appears flat, like a painting. What they see is an image 50% larger than what we see. So an average dog appears to be the size of a pony when viewed with one eye. As objects get closer and we pass them the object gets bigger in size until it disappears into the blind spot near their tail.
As far as colors, they see red as a grey or brown. Anything appearing green or yellow to us is very vivid to their eyesight.
When I compare a straight on headshot of my other mare Pearl, it is immediately obvious that when I took a picture with her looking straight at me her eyes are larger and she is able to see more in front her then Minnie sees. So her blind spot isn’t as big as Minnie’s, unless she is holding her head really low.
With Pearl’s eye placement and the size of her eyes, the blindspot in front of her looks like it is less than a foot. Now wonder she was so good at jumping, she could see the jump.
So imagine what we are asking a horse to do when we put them over a jump that is directly in front of them. If we don’t give them their head so they can jut out their nose to see the jump we are asking them to trust us to leap blindly (just how blindly depends on their eye placement in the skull) and they are relying on their rider to be competent enough to give them the proper cues for when to jump. In the middle of the jump, it comes into view in the monocular vision, it appears larger than we see it, and they have to judge the width of the jump while they are in midair.
Another factor with their vision is that it takes their eyes 45 minutes to adjust to low light. So when we ask them to step into a horse trailer, they literally can’t see clearly where they are going or what is around them for 45 minutes. That also made me think of how many shows are set up with the warm up ring outside in bright daylight and the dressage ring inside in low light.
Is it any wonder that they turn and bolt when they can’t see what is coming toward them. Minnie and I are working on this. Now that I understand that she has a larger blind spot in front of her than Pearl, I know that she needs more information about things coming straight toward her. When I gave her access to that information by turning her head, she was instantly fine. My habit when a horse shies has been to have them directly face the object. I will not be doing that anymore. I now know that if it is within 20 feet, all she is seeing is a blur in front of her.
If anyone is interested in reading an article about how the horse see’s, here is a link to an excellent article published by Horse and Rider:
After that publication there was further research done in Ireland and the UK that found that horses can be near and far sighted. As well as that the blind spots can vary in size due to the size of the eye and eye placement in the skull. Here is a link to a more technical article published in the International Journal of Zoology in 2009.