The tapetum lucidum is a layer of tissue in the eye of many vertebrates. 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 superior night vision of some animals. Many of these animals are nocturnal, carnivores, or sub-terranian species and even deep sea ocean mammals.
Most primates, including humans however, lack a tapetum lucidum, as primates traded this ability long ago in the evolutionary path to gather and forage for berries and vegetation.
Eyeshine is a visible effect of the tapetum lucidum. When light shines into the eye of an animal having a tapetum lucidum, the pupil appears to glow. Eyeshine can be seen in many animals, in nature and in flash photographs. In low light, a hand-held flashlight is sufficient to produce eyeshine that is highly visible to humans (despite our inferior night vision); this technique, spotlighting, is used by naturalists and hunters to search for animals at night.
Ok, so, what are we questioning you say? Why would Sasquatch have a large tapetum lucidum? Primates again have traded that along the evolutionary path to forage and it's been well documented.
Primates are also known to not see well at night, however Sasquatch reports flourish in the night.
Unless that is Sasquatch is not primate........
While this leads to many different theories the persistent trait of eye-shine is one to question, if Sasquatch is indeed a primate? How would that be possible.
Another question to ponder, is it possible Sasquatch is subterranean?
And if Sasquatch is a primate and has an evolved tapetum lucidum perhaps as it evolved, it adapted to life underground to avoid detection, as humans encroached on its territories and potentially turned it into an earth dweller by day v.s. a forager by day.
Would that explain the lack of finding them in the day time? Do they live beneath the earth in caves, or under trees?
What say ye? Stay tuned to upcoming episodes.
Your comments welcome