Up until recently, I thought I had a pretty good understanding of how horses see. Being the egocentric human being that I am, that understanding equated to, “Well, they must see like us, duh!”. But after starting to read Horse Brain, Human Brain by Janet L. Jones, PhD, I started to realize that they were huge holes in my knowledge of equine vision.
This week, I wanted to share seven things that I learned from the book that surprised me and may surprise you as well! Please enjoy!
P.S. I highly recommend reading ‘Horse Brain, Human Brain” for yourself!
1. Horses have poor visual acuity.
Visual acuity refers to the ability of the eye to distinguish shapes and the details of objects at a given distance. Many people assume that horses can make out tiny details just like humans but this isn’t true. Normal acuity for humans is 20/20 whereas equine visual acuity falls in the ranges of 20/30 to 20/60.
Check out more information on visual acuity, here!
2. Horses cannot focus on details.
We can focus on individual details of a scene very easily thanks to the anatomy of the human eye allowing for visual accommodation. Horses do not excel at visual accommodation and are unable to see things that are held close to their faces. This is why some horses may startle when you hold something up to their nose abruptly.
To help your horse see something you are holding easier, be sure to hold it away from you while standing several feet away, allowing the horse time to look at the object. The little focus horses have occurs slowly so be patient when offering a look.
3. Equine range of view is about 340 degrees.
The human range of view is only about 90 degrees compared to the equine’s 340 degrees. The areas directly to the side of each eye are the clearest for the horse. So next time your horse spooks at “nothing”, remember that they probably see something that you don’t!
4. Horses adapt to darkness slowly.
Horses have evolved in environments where the sun slowly rises in the morning and slowly sets in the evening. Sudden darkness is typically not something they need to worry about. Most horses aren’t going to waltz into dark caves.
This slow darkness adaptation poses a challenge for horses when entering dimly lit barns or arenas. It takes the horse 45 minutes to adapt to sudden changes in light. 45 minutes! That means that by the time your horse has adapted to the new lighting conditions, you’re probably done with your ride and changing them again! This is why bright lighting in arenas is super critical.
5. Horses have poor depth perception.
Horses have poor depth perception due the side-placement of their eyes and are typically unable to see the same object with both eyes. This is especially important to consider when jumping. Riders should always aim the horses for the center of the jump so that the horse can clearly see the jump with both eyes.
6. Horses are not colorblind.
Many people assume that horses are colorblind but this is technically not true. Horses can see shades of both blue and yellow. Horses have a difficult time seeing brighter shades of orange, red, and green. This is a key fact when designing jump courses and other equine equipment.
7. Horses compensate for poor sight with other senses.
Now that we know that horses eyesight is poor when compared to humans, it is important to recognize the importance of the horse’s other senses. When a horse can’t see something clearly, they will smell it. If they see movement in the distance, they will listen for noises from predators. The horse’s ability to utilize their senses in such tandem and harmony is truly something to be marveled at and explored more and more.
Thank you so much for reading about equine vision! Did any information in this post surprise you? Let us know! We’d love to hear from you!
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Bonus resources and reading materials
- Horse Brain, Human Brain – Janet L. Jones, PhD
- Vision in the Equine – Iowa State University
- How Do Horses See Colors – Equine Simplified