Shining a Light on Eye Shine

Isn’t it interesting that the more you learn, the more you find out how much you don’t know?

I’ve always considered myself a very critical thinker. In fact, that’s the driving motivation behind this blog, to bring a level of critical thinking to the world of Bigfoot (there are others that share the desire for logical conclusion and rational thinking and they will be highlighted in a post upcoming).

I’ve long taken pride in being able to listen to (or read) an encounter and, clearly and concisely, weave and spin between the lines of story and phantasm to reach a verdict as to the accuracy of all or parts of a story. This could be misconstrued as looking for an opportunity to call someone a liar, of which I can assure you, is not the case. I badly want to believe every single encounter I read or hear. I so terribly wish that I could mute certain outrageous pieces of stories so that the rest of the story, which seems possible, would not be tainted. Alas, I can’t. For this reason I’m often “that guy” who responds to recordings of most “calls” as “Coyote….fox….mountain lion….dog…”

I’m that buzzkill who chalks just about 90% of encounter stories up to misidentification, attention seeking, or pure and simple inebriation.

I don’t want to. Really.

All of that being said, there has always been one piece of an encounter story that I could not dismiss and would often look at as a “plus” in the “possible” coloumn” when trying to seperate fact from fiction in bigfoot eyewitness encounters.

Eye shine.

Eye shine, put simply,  is the reflected glow in the eyes of some animals in darkness.

Now, that definition leaves a lot to be desired but it will work to get us started here.

Eye shine is a mainstay in many sasquatch encounter stories. After all, many stories take place after dark and one would be inclined to believe that eye shine would be a viable tenant of a credible story. There is nothing inherently “weird” about eyeshine. It is a physiolgical process/mechanism known to exist in some species of animals who possess the necessary infastructure within the eye to reflect an outside light source. Most animals that posess the necessary pieces within the eye to emit eyeshine are nocturnal. Now, we don’t know if bigfoot is truly nocturnal, diurnal, or simply whenever…urnal. What we do know, however, is that many bigfoot encounters happen at nightime. So, at least we have that.

Unfortunately, that’s where a lot of the plausible correlation between bigfoot and eyeshine begin and end.

Applying Critical Thinking A.K.A. Here comes the Buzzkill..

As is in the spirit of this blog that we must now dissect and apply what we know to about eyeshine to the subject of sasquatch.


As in all cases, we are applying something that we know (the physiological processes required to emit eyeshine and the animals that pocess the necessary mechanisms to do so) to something that we literally know nothing about (factually speaking; Bigfoot). You can respond to any of these arguments (or my articles in general) by saying something along the lines of, “Well yea, but bigfoot is completely different. Bigfoot could have eaten a special flower that used to exist 20,000 years ago and that flowers nectar began to mutate Sasquatch on a genetic level so now they have eye shine and stuff… You don’t know.”

You know what?

You’re right.

Sasquatch could also be so elusive because they stole fairy dust from Tinkerbell and mixed it with unicorn hair to create a super potion that makes them totally invisible to humans and smell like pixie sticks.

Both arguments possible. Both highly unlikely.

But, I digress..

In my usual manner, I’m going to look at eyeshine and sasquatch through my particular “filter” which is assuming that sasquatch is simply an animal, likely a primate, and assess the situation from there.

With the above statement, we need to first establish what eyeshine is on a biological level

Here’s what we’ve got, documented scientifically;

1) Eyeshine is caused by a layer of tissue in the eye, lying behind the retina, called the tapetum lucidum.

The tapetum lucidum /təˈptəm/ (Latin: “bright tapestry”, plural tapeta lucida)[1] is a layer of tissue in the eye of many vertebrates.[2] Lying immediately behind the retina it reflects visible light back through the retina, increasing the light available to the photoreceptors, though blurring the initial image of the light on focus. The tapetum lucidum contributes to the superiornight vision of some animals. Many of these animals are nocturnal, especiallycarnivores that hunt their prey at night, while others are deep sea animals.

Definition pulled from Wikipedia and

Sasquatch are often considered nocturnal or at least opportunistic hunters that seem to be active at night. The tapetum lucidum is often found in nocturnal animals. Awesome. This makes sense.

2) The tapetum lucidum is found in a great many animals including;

Dogs (both wolves and domestic), cats (again, both domestic and wild), cows, horses, sheep, sharks, rays, skates, crocodiles, marsupials, and bats.

Noticeably absent?

Primates. Great apes, specifically.

In fact, the only primates that have tapteum lucidum are several species of lemur (Strepsirrhini and Eulemur) 

Before you go all Melba Ketchum on me and begin the “Sasquatch could be a lemur…ask Melba. She knows. DNA samples, you know. She has DNA that shows lemur”, remember this;

You’re arguing for Melba Ketchum.

Think about it.



Ok. Good. Now that you’ve come to your senses…Let’s continue…

The fact that there is no precedent of tapetum lucidum in any prmate who’s characteristics even slightly resemble sasquatch should be enough to give us pause when using eyeshine as a “plus” while deciphring the crediblitiy and/or accuracy of a suppossed encounter.

As mentioned earlier, however, there is no definitive in this situation. Until a specimen is found, alive or dead, we honestly have no idea what we are dealing with when it comes to Bigfoot.

All we can do is critically analyze the situation using what we do know to be true, within the context of our current scientific understanding, and apply this knowledge to our study of an unknown.

Sadly, I have had to rethink the value I placed on the presence of eyeshine in supposed bigfoot encounters. With no precedent in the known animal kingdom, specifically in great apes, I find it unlikely that sasquatch would posses the necessary structures to display such a thing.

In conclusion there is no conclusion and there will not be any conclusion until we have the creature to study.






One thought on “Shining a Light on Eye Shine

  1. Bears have eye shine… you see it all the time on Trail Cameras. Interesting about primates not having eye shine… who knew? Also if it is known that a Sasquatch is standing there in the dark and eye shine is seen (or better yet captured on a photograph… oh yeah… forgot… no pictures concerning Sasquatch) and verified by more than one respected individual… then that might also go along with proving that Sasquatch is not a primate.


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