Are Horses Color Blind? (Answered!)

While tending to my horses with my son the other day, the horse was being a bit agitated for some reason and my son wondered if it was because I was wearing such a bright red jumper.

I thought he might have been right at first and so I took it off and put it somewhere else, but my horse’s behavior didn’t change.

He was fine in the end, but it did get me wondering about something.

Could my horse even see the red of my jumper?

Can horses see any colors?

So I decided to look into it.

So, are horses colorblind?

Horses are not completely colorblind, although they have a greater difficult separating certain colors and some colors lack any pigment for horses. Horses do not need full color vision like, say, birds do, and as much as we might think we do, not even our own vision is strictly full color.

Horses are not colorblind, then, but they also do not see in full color.

Full color vision is actually quite rare in animals, and is most common in birds, who need to distinguish shapes on the ground from a high vantage point.

Horses don’t have these complex needs, so they lack the full spectrum of color vision and have trouble distinguishing many pigments.

So, let’s look at what colors they can and can’t see.

What colors can horses see?

Horses have what is called dichromatic vision, or two-color vision.

This means they distinguish colors in two wavelength regions of visible light.

Compare that with our own vision, which is trichromatic.

Essentially, horses naturally see the blue and green colors of the spectrum and the variations based upon those two colors.

They cannot, however, distinguish red.

Research shows that a horse’s ordinary vision is like red-green colorblindness in humans, in which certain colors, especially reds, seem much greener.

This is an optical deficiency in humans, as opposed to the ordinary vision of a horse.

This vision is a result of horses having two types of cones in their eyes.

A short-wavelength cone, which distinguishes blues, and a mid-to-long wavelength cone, which distinguishes yellowish colors.

It’s thought that this structure arose as a result of horses being most active at dusk and dawn, when these colors are more prominent and when the rods of the eyes are especially useful.

This is often taken into account for show jumping horses, who might struggle to gauge the jump if they can’t distinguish the obstacle from the ground.

Horses are by no means fully colorblind, then, but they are significantly less sensitive to the full spectrum than we are.

So, how does this colorblindness manifest itself?

Can horses see the color white?

In the sense that horses do often see the color white, they certainly can.

Often, their inability to see in three spectrums will mean that any two colors mixed together are likely to produce a greyish white in their line of vision.

Horses might have a difficult time distinguishing actual whites from things in their vision on the color spectrum that they are not sensitive to.

As we often joke with dogs, much of what we see as dynamic joining of two colors to form a new shade, horses will simply see as gray.

So, yes, horses can definitely see white.

White, technically speaking, is less of a color and more the result of many types of color mixed together.

Take the spectrum of natural light from the sun; it appears whiteish yellow to us because all the colors of the spectrum are mixed together.

The same is true of horse vision, except that it only takes two colors being mixed up to produce this white.

So, yes, horses definitely see a lot of white!

Can a horse see in the dark?

So, how does this influence their vision in the dark?

Well, as I said, one theory indicates that horse vision developed in the way it did because horses are most active during dusk and dawn.

So, naturally, you’d think they have great night vision.

And, indeed, they do.

Horses have excellent night vision.

On a night lit only by a partial moon or even bright stars, they can see as well as we could during the day.

Their vision can take some time to adjust when moving between differently lit environments, but in general their night vision is much better than ours.

Their colorblindness doesn’t play as much of a factor in this.

In part, its simply about the size of the lenses in a horse’s eye.

Horses’ eyes are much larger than ours, so they can absorb a lot more light.

This makes it much easier for them to get a better picture of a dark environment.

Horses have perfectly adequate vision for their own purposes, then.

They can distinguish colors as far as they need to, and in a few places are directly blind to certain colors, or at least they have a lot of trouble distinguishing them.

As I said at the beginning, very few animals do have full color vision, as it’s just not necessary.

Our spectrum of color vision has no doubt helped us reach the advanced point we’re at now, but horses are quite happy doing what they’re doing.