Eigengrau: The Color You See When You See Nothing

Close your eyes for a moment. Don’t worry — we’re not going to play a trick on you or steal your wallet. Take your time. We’ll still be here when you get back.

All done? Good. Now, describe what you saw. No, the answer is not “nothing.” You certainly saw something. For one thing, you saw a color. What was it?

If you answered “black,” that’s incorrect. Sadly, there aren’t any exciting consolation prizes for those who failed to get the correct answer.

If you answered “eigengrau,” congratulations! You win the exciting grand prize of having the smug satisfaction that comes from knowing you are a wee bit superior to the ignorant slob sitting next to you.

Yes, eigengrau is what you saw when you closed your eyes. You might be thinking, “Eigengrau? Is that some kind of exotic German cheese?” As delectable as that sounds, eigengrau isn’t a food; it’s a color. Coming from the German word for “intrinsic gray,” it is the color your brain perceives in perfect darkness.

Philosopher and physicist Gustav Fechner (1801-1887) is believed to have coined the term in the 19th century. He conducted an experiment in which he tried to measure the limits at which people perceive gradually-increasing stimuli. Out of these experiments, he found that even in the total absence of light, people still see things. 

We owe our vision to the dynamic duo inside our eyes: rods and cones. Cones are the flashy, color-savvy ones, picking up on all the vibrant wavelengths of light. Meanwhile, rods may not know their magentas from their cyans, but they really step into their own when we need to see in dimly-lit places.

If you have been enjoying a bright, sunlit day and abruptly step into a dark cave, your eye hand over control from the cones to the rods. They work their magic, straining to find every available photon. In the total absence of light, those rods are still doing their thing. They continue shooting signals to our brain like a sly glint of light in the dark. The result is that our eyes perceive a smoky color that is not quite black. In other words, eigengrau.

If you keep your eyes closed long enough, you will likely also see swirling dots or waves of color or light. That phenomenon is called eigenlicht (German for “intrinsic light”). You see this for the same reason.

Keep your eyes closed even longer, and you may see a chihuahua in a suit of armor, fighting off invading swarms of tadpoles with an arsenal of flaming pickles. That phenomenon is called a “dream.”

By the way, why am I the only one who seems to have that dream?

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