A Bears Eyesight Is better Than You Think

Most of us who spend anytime hunting, or reading about hunting bears have been told although a bear's sense of smell is superb, their eyesight is poor.

It turns out that recent research shows that is NOT the case. The eyes of a deer are larger in comparison to their body size than many animals. Their position on the head does NOT allow for much eye movement which is diverse from humans and other predators. A bear on the other hand has much smaller eyes, however they move more freely than a whitetails. Since the deers eyes are more or less stationary and therefore a deer has to move its head to see its surroundings, a bear can move its eyes and take in more terrain without moving its head to do so.

The eye is made up of (5) different parts:

• Cornea - protective layer over the lens /Humans have an UV filter and on animals it is CLEAR
• Lens - right behind the cornea and collects and directs light into the retina
• Pupil - opens and closes to change amount of light passing into the eye
• Retina - located in the back of the eye and light that hits it is sent to the brain via the optic nerve
• Optic Nerve Head - sends light

Apparently there are differences between a PREDATOR'S EYES (Human, Bear etc.) (vs.) a prey species eyes (as an example whitetail deer). One such important area is how the eyes focus. Humans and Bear's are similar in that we have a very small field of actual focus in our peripheral vision. We can see as an example an entire field or section of woods, however our eyes (and the Bear's) then FOCUS on a particular section of that field or woods. Deer on the other hand have a WIDE area that is in complete focus. Deer have a narrower band from top to bottom than we do, however the entire area they see is in FOCUS while our focus is more limited to a much smaller area. To make it simple when a whitetail is looking straight ahead, almost its entire horizon is in focus and they do not have to bounce their eyes back and forth and up and down to achieve that focus. A Bear's eyes are positioned more to the front of its head while a deer's are more to the side of its head. You might say that Bear's have binocular vision for the entire 120 degrees of their field of view.

RODS (VS.) CONES:

I teach NYS defensive driving classes and always try to mention that Whitetails have more rods than cones. Why is this important? They do not break down the color spectrum as well as you and I do, however they can easily detect the slightest movement in their field of view. In other words a deer may or may not see you and identify you as a threat simply because you are wearing  an orange vest or hat if you are perfectly motionless, however if you adjust your hat, check your wrist watch, scratch that itch on the side of your nose etc. he will likely detect that movement instantly anywhere it occurs in his peripheral vision.

Deer are said to have approximately 20/40 vision while perfect vision in humans is said to be 20/20. A humans pupil opens and closes rather quickly while a Bear's open and closes mores slowly, however the bear's pupil opens almost 2X as wide as ours. Bears and deer have much better LOW light vision  than a human does than we do. Bear's have a substance called "Tapetum Lucidum" on the retina which is largely responsible for this. Bear's have approx 10X the number of rods as humans have.

Deer can detect movement better than a bear and this of course ups their survival rate. Bears are a predator species and the detection of the slightest movement is apparently not needed by them as much as it is the deer.

Both deer and bear have considerable advantageous to humans as far as eyesight goes in general. I believe it is simply because the good Lord made them that way.

You can bet when that big bear comes to a bait site at very last light, that he is seeing things a whole lot better than you and I are. Both the whitetail and that big bear win the contest hands down when it comes to their sense of smell. They certainly take advantage of what their eyes can see, however I believe their noses are probably the FIRST line of defense for both species.

Dan

Genesis 1:31 King James Bible (Cambridge Ed.)
And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.