Monster of the Week: The Cyclops

Polyphemus the cyclops by Pellegrino Tibaldi, 1550. De Agostini/Getty

What a terrifying creature is the cyclops! These gigantic humanoids are often perfectly happy to occupy themselves with shepherding, blacksmithing and other such trades. When enraged, however, their wrath is horrific indeed.

Take for instance the Turkish cyclops Tepegöz from "The Book of Dede Korkut." Born to a fairy and fathered by a human rapist, this vengeful creature once demanded to eat 60 men a day and the mere sight of him could make your gallbladder burst with fear.

Never trifle with a cyclops, lest you suffer their myopic rage.

Biology of the Cyclops

What are we to make of that strange, solitary eye?

Real-life cyclopes.
Roland Birke/Getty

Discounting birth defects and injuries, most sighted natural-world organisms boast two eyes rather than just one. In humans and many other creatures, both eyes work together to provide binocular vision. Still other creatures, such as various lizards and birds, use their eyes separately in monocular vision.

But do any other natural-world organisms boast a single eye? Yes, but we have to do a bit of evolutionary backtracking to find such a departure from biological norms.

There's an entire genus of copepod fittingly called "cyclops" because the 400 odd species boast a single red or black eye. They're highly successful creatures, but grow no larger than ½-5 mm.

Third and Only Eye

By some accounts, the mythic cyclopes gave up one eye (or perhaps both their stereoscopic eyes) in order to gain the gift of prophesy.

A 4th-century Roman image of the cyclops Polyphemus with three eyes.
De Agostini Picture Library/Getty

This is especially interesting since Western depictions of the cyclops often feature the fleshed-over sockets of atrophied peepers beneath a centralized forehead organ, the very spot where Eastern traditions place the "third eye" of supernatural sight.

We often equate that invisible third eye with the pineal gland, a pine cone shaped organ buried in the skull that grows no longer than a .8 centimeters. It produces several important hormones, including melatonin in response to environmental lighting.

In lower vertebrates such as fish and lizards, the optically-engaged pineal gland actually stems into a parietal eye. Parietal eyes typically appear as a grey oval on the foreheads of certain burrowing lizards (among other creatures). While the animal doesn't quite see out of this structure, the parietal eye is photosensitive and influences circadian rhythm.

De Agostini/Getty

One can't help but wonder if the cyclops boasts a highly-evolved parietal eye. Perhaps these giants lost their sight as they evolved to thrive in subterranean habitats and the dark pits of Tartarus. As we discussed in a previous Monster of the Week post, we often see this loss of sight in troglofauna as creatures adapt to a lightless world.

In the dark, perhaps the cyclops's parietral eye "opened" over time and quickly evolved into a higher sight organ when the cyclopes once more emerged into the sunlit world. And if one were to factor in unproven connections between the pineal gland and the production of the psychedelic compound DMT? Well, perhaps that's why these one-eyed beings see stranger and farther than most...

Natural World Explanations

There are of course natural world explanations for the creature, ranging from the forehead lanterns of Pelasgian miners to the protective eye patch worn by blacksmiths (this prevented sparks from blinding both eyes at once). The skulls of prehistoric Mediterranean dwarf elephants also factor into explanations. What else could that central nasal opening be but a great eye socket?

Monster of the Week is a - you guessed it - regular look at the denizens is of our monster-haunted world. Sometimes we'll focus on the cultural aspects, but mostly we'll look at the possible science behind a creature of myth, movie or legend. Be sure to explore the Monster Gallery as well as the Monster Science video series.

About the Author: Robert Lamb spent his childhood reading books and staring into the woods — first in Newfoundland, Canada and then in rural Tennessee. There was also a long stretch in which he was terrified of alien abduction. He earned a degree in creative writing. He taught high school and then attended journalism school. He wrote for the smallest of small-town newspapers before finally becoming a full-time science writer and podcaster. He’s currently a senior writer at HowStuffWorks and has co-hosted the science podcast Stuff to Blow Your Mind since its inception in 2010. In his spare time, he enjoys traveling with his wife Bonnie, discussing dinosaurs with his son Bastian and crafting the occasional work of fiction.