WHY BLAZE ORANGE DOES NOT SCARE DEER

Deer do not view the world the same as do humans.  This is not just because they are a different species of mammals.  They are just built differently.  I have often wondered why deer do not react to such a vivid color.  A little research and an interview with a biologist friend resulted in the following information.

 Sitting in a treestand or stalking through timber deer do look at the hunter.  Yet there is no difference when I am in a blind and wearing blaze orange.

 They do not seem to react even though there might a hunter easily within their vision.  On other occasions, we all have seen a deer look at a hunter in the tree and suddenly bolt from the scene.  What is the difference?

 Mammals have eyes that contain a retina on the back of the eye ball.  There are about a quarter billion photo receptors in the retina.  They are called rods and cones.  The rods and cones absorb different wavelengths of light. 

 We use the rods for dim-light and vision to the peripheral areas surrounding us.  Although they are more sensitive to light, they do not provide either sharp images or color vision.  That is what makes low light images appear fuzzy as does the images to the sides of our field of vision. Rods are very sensitive and respond best to dim light.  They absorb all wavelengths of visible light but their input is perceived only in gray tones.

 The cones work in bright light to give us great color vision.  Cones need bright light for activation but have pigments that furnish a vivid color view of the world. 

The addition or lack of light as when we move from darkness into bright light is adapted to automatically as the retina adjusts to the amount of light present. 

Deer have more of a concentration of rods (best for night vision) than man but a lesser concentration of cones (best for day vision.)  Additionally deer have a pupil that opens wider than man and allows more light to be gathered in by the eye in low light.  They also have a reflective layer in the back of their eye called the tapetum.  It is what makes their eyes shine at night.  They use it to absorb twice the light a human can under the same conditions. 

 Unlike man, deer have no red-sensitive cone cells in their eyes.  This means that they cannot tell red or orange from green and brown.  In addition they have different sensitivity to various wavelengths of light.  Deer see short wavelength colors such as blue and ultraviolet (UV).  Humans cannot see the UV light.  They are less sensitive to orange and red.  The end result is that red and orange look darker to deer than to humans. 

With this situation, bright colors such as blaze orange look bright to humans. The human eye is protected by a filter that blocks about 99 percent of UV light from entering the eye.  It is like sunglasses. 

Blaze orange absorbs UV rays that humans cannot see and turn them into longer wavelengths they can see.  The orange reflects less UV that deer sees well and more of the rays they do not see well.  The end result is that deer see a greater difference in UV treated fabrics than humans.  Fabrics become UV treated when they are washed in modern dyes and brighteners.  There are products on the market that will do away with most of the UV that modern dyes and brighteners implant. 

The UV problem is only present during low light conditions.  This would generally mean early morning and late evening, times when most deer hunting takes place. 

Products to the market this fall use a patented combination of high intensity UV chemical in combination with legally approved daylight fluorescent safety orange to equally stimulate the blue-sensitive and yellow-sensitive cells of a deer eye.  This color correction perceived by the deer becomes a neutral gray.  It is still highly visible to other hunters and legal to wear in states that require hunters to wear unbroken blaze orange. 

Because deer are better able to see the UV spectrum, they also see less fine detail.  Hunters could be better off using camouflage pattern clothing.  Blaze orange clothing in a camo pattern would probably be the best choice from a hunter’s standpoint.  However, blaze orange camo is not legal in some states.  

Scent and movement are probably more important in deer hunting than is blaze orange clothing.  The deer’s vision is designed primarily to detect motion.  That is why those deer will stare at you a treestand and not panic.  If the objects in their view do not appear to be a threat, the deer will move his head from side to side to increase his dimensional perception.  It makes objects stand out from the background.