Cows and calves can see color. They just don’t see the same range of colors as you and I do.
Cows are red colorblind. That means they don’t have the “red” color receptor in their eyes (retinas). They see every shade of red as a version of grey or black. They can’t see any colors that have red light in them. For example, purple will look blue to cows.
Their world isn’t totally shades of grey, black and white. They can see shades of yellow and blue, but in a faded version. Colors such as orange are bright for cows, but they don’t see green very well. When a cow looks at a tree, it looks like a tree! They just don’t see the bright range of vivid color that we see. They see a duller version without red tones.
The Cow Eye
A cow’s eye is about 1.5 inches. The iris, which gives an eye color, is brown. You may have blue or green eyes, but a cow will always have brown eyes. A cow’s pupils are horizontal compared to our round ones. They can’t roll their eyes up and down; they need to move their entire head. To focus on objects on the ground, they need to lower their heads while you can just lower your eyes and look down. They also have weak eye muscles so they cannot focus on things quickly.
How far can cows see?
A cow’s eyes are located on the side of their head instead of in front like yours. This gives them a broad picture and they can see almost to their rear end. When they have their head down eating, they can see all directions without moving their heads. But, they can’t see directly in front of them. That’s why when we move cattle, we often swing our arms out wide so they can see the movement. When farmers walk up to cows from behind, we calmly touch their rump so we don’t startle them.
Cows have issues with depth perception. They can’t tell how far away or how close an object is in front of them. They spook easily at shadows or other objects with sharp contrast. If there’s a black fence in front of a white barn, they will shy away from it. And, they tend to be sensitive to sharp contrasts in color.
In truth, cows can smell better than they can see! A cow can smell scents from as far as six miles away!
Can cows see at night?
Cows can see better in the dark than humans. That’s because they have a special reflective surface behind their eyeball that reflects light back through their retina a second time and lets them see in low light. This helps them to see their food or walk around in the dark.
Can cow eyes get diseases?
Just like humans, cows and calves can get a condition called “pinkeye”. Their eye will become cloudy, drip water, and they often partially close their eye lid. This disease is spread by flies. Fortunately, there are vaccines and successful treatments to cure this condition. We have had a few cows get eye cancer on our farm but that is very rare and we work with a veterinarian to make medical decisions to care for cows with cancer.
You probably have never seen a cow wearing glasses. There are no cow eye doctors that can test a cows vision and prescribe glasses to wear. Just think how hard it would be for a cow or calf to even wear a pair of glasses!
Fortunately, cows don’t need precise vision to read a recipe book or an educational magazine. They have farmers like me to do that. Instead, they can survive with limited vision and rely on their nose to help find things.
A note from Farmer Pam:
Thank you for emailing questions or posting them on the "Contact Your Farmer" link through Discover Dairy. I will answer more of your terrific questions in future blog posts.