Rods and cones, all of our eyes contain them. They’re photoreceptors, the cells in our retinas processing light into signals for our visual system. Rods react in low light conditions like when you wait in a just-darkened arena for a concert and your eyes adjust, trying to determine if the band is walking on stage yet. Otherwise the cones activate and do well in high light like when the band performs energetically and resplendent pyrotechnics or lasers or spotlights flash yet you still track the dancing lead singer. By analyzing the spectra of cone wavelength absorption our visual system determines color. Science can be fascinating.
The prevalent number of cone type photoreceptors in a human eye is three, trichromacy. I fall into that category, so I’m a trichromat. The dichromats out there have two functioning types of cones–which is usually referred to as color blindness; monochromats perceive light one-dimensionally.
Cone analysis can be tedious. Let’s stick with the music. For once, I’ll liken my cones to another three member group, Nirvana. Perhaps others with three cones would prefer bands like The Police or Muse. Not everyone loves grunge, I get it. For those perceiving the visual world with two cones, you’re like The Black Keys or the White Stripes, still jamming but a distinct sensory difference.
How many guitars, I mean photoreceptors are enough? Would you opt for a fourth cone, to be a tetrachromat? Would you want as many types of light receptors as possible? You could take your sensation from dull to brilliant. With four cones, you’re in concert with CSNY, The Beatles, or of course, the legendary trippy band, Led Zeppelin.
According to Concetta Antico, a lady lives in San Diego who was clinically tested and proved to have a fourth cone, this brilliance can be a bit…distracting.
“Let’s take mowed grass. Someone who doesn’t have this genetic variation might see bright green, maybe lights or darks in it. I see pinks, reds, oranges, gold in the blades and the tips, and gray-blues and violets and dark greens, browns and emeralds and viridians, limes and many more colors — hundreds of other colors in grass. It’s fascinating and mesmerizing.”
To see colors within other colors sounds incredible. I found her interview published in New York compelling. It made me wonder, can you fathom living visual life even more dazzling than a tetrachromat as a pentachromat as many birds and butterflies? It would be stunning, fleeting, temporary in the manufactured brilliance of boy bands with images similar to a head injury–hard to ignore with lasting fragmentation. Hmmm.
And let’s not forget those rare Mantis shrimp swimming the ocean with twelve color receptors. Twelve. A marvel they get anything done. Of course they can’t live on land, they’re too busy with Sebastian under the sea staring at the sand, a small crustacean orchestra without a conductor.
The next time you attend a party with good music, taking the scene in with your rods and cones, munching some delicious cocktail shrimp, consider how common those photoreceptors are that you would’ve digested had the cook not deveined that seafood. That average shrimp, he’s not looking at you anymore.
Photoreceptors are neat. Would you opt for another cone? Would you give one up? Do you have more or less than three functioning photoreceptors? How does it affect your vision? Tell me about it.
Adventures in Low Vision 
All I can tell you is that without my dark glasses, even a gray roadway looks neon. Without my dark glasses, I get migraines and the worst part of the problem is the red end of the natural light spectrum.
I’ve worn very dark glasses inside for so long that my kids wouldn’t recognize me if I took them off. 🙂
That must be quite the suntan line from the glasses with the FL sunshine.
Oddly, the only time I’m in the sun is to go for walks. But it’s enough to make my face a few shades of beige darker than my very pale legs. 🙂
I’d like to have another cone but even more than that I’d like the kind of night vision an owl has. Just the thought of moving quickly down a sidewalk at normal speed without fear of tripping or bumping into something would be awesome. Perhaps owl-sight contacts will be available someday in our brave new world.
The visual acuity at night of an owl would be a great characteristic.
This reminds me of that scene in Girl With a Pearl Earring when the painter teaches Grete to see multiple colors in a (supposedly) white cloud. It’s such a beautiful moment and reminds one of the nuances in the things around us.
That is a great parallel moment of nuance in color.