Over the years, you have probably read stories and heard tales about deer being color blind and how bad a deer’s vision is compared to that of a human. You may be interested to know that a recent study by researchers from the University of Georgia’s Warnell School of Forestry and Natural Resources, has shed new light on whitetail vision.
Scientists remind us that eyes function as they do to give sight because of specialized nerves called rods and cones. Color vision in both animals and humans is the result of different photopigments (or photoreceptors). It is the light-sensitive pigment in rods that allow us to see in low light, which would include the important times of day for hunters — dawn and dusk.
Researchers have known for many years, through anatomical studies, that deer eyes have many more rods than humans. Additionally, deer have what is called the “tapetum lucidum,” a reflective layer that gives deer the “eye shine” you can see in nocturnal photos. This unique layer also reflects light back over the rods and cones, giving deer a clear advantage over humans when in comes to being able to see in a low-light situation.
Human and deer eyes differ in that humans have tri-chromatic color vision, or three types of photopigments present in the eye that enable us to see short, moderate and long wavelengths of light. These wavelengths correspond to blue, green and red colors. Deer eyes, on the other hand, only have two photopigment types, or dichromatic color vision. Game biologist and scientists are convinced that deer can primarily see short-wavelength blue light, and moderate-wavelength light that is likely perceived as something between red and green.
The cones in a deer’s eye are distributed across the back of the eye on a horizontal plane, which is much different than in humans. The deer’s lens is unable to adjust to objects at varying distances like that of humans. Because of this, deer do not see as clearly as we do. The deer does seem to have better peripheral vision than humans. In fact, an object out to the side of a deer’s sightline is equally in focus with an object he may be looking at straight on, which means a deer can see you without necessarily looking straight at you. The truth of the matter is that a deer’s eyes are primarily designed to detect movement.
The unique thing about the Georgia study is that it moved beyond what can be learned by dissecting a deer’s eye to what was actually observed from live deer observed in the experiment used by these researchers.
Biologist Dr. Bradley Cohen actually trained does to associate light wavelengths with a food reward in a test to determine how well deer can really see. Two empty food troughs were available to the deer, but the doe would only receive a food reward when she chose to eat from the trough where an LED light stimulus was illuminated. After a brief training period, deer were tested on six different light wavelengths with varying intensities to establish what colors of light they can see.
Dr. Cohen deduced that, looking at the color spectrum, deer see blue colors best and red colors the worst. Further, the test showed that deer can also see greens, yellows and UV light, but they don’t seem to be able to differentiate between shades of color to the extent that humans can.
What Should I Wear?
So, when you are going through your hunting wardrobe, the first rule should be to avoid wearing anything blue. Camouflage is okay, but avoid any pattern that has a lot of white in it because white reflects all colors,
including blue. It is better to chose camouflage that breaks up your silhouette over camouflage that features subtle shades of green and brown that makes you appear as a moving blob to the deer.
Despite its popularity, there is a lot of science that suggests you don’t really benefit from wearing camo, although many hunting organizations recommend it. If you wear green, red, or orange, you can blend in with your surroundings, as far as a deer is concerned. But again, you should stay away from blue and UV brighteners.
Still, in the scheme of things, what a hunter wears does not matter as much as movement, which is what often causes a deer to flee. And the animal’s keen sense of smell tops its vision when it comes to its human detection radar.