“Color itself is a degree of darkness,” Goethe wrote in his theory of color and emotion. Although it was at bottom a misguided refutation of Newton, Goethe’s study of colors, in addition to inspiring artists and philosophers as wide-ranging as Schopenhauer, Gödel, and Kandinsky, inadvertently posed one of the most fascinating questions in neurology: What if color can, indeed, be experienced as degrees of achromatic darkness, and this mode of perception is not a disability but a difference in ability?

It fell on the irreplaceable Oliver Sacks (July 9, 1933–August 30, 2015), the Gödel of neurology and the Goethe of science writing, to answer that question.

A voracious lifelong reader, Dr. Sacks had grown enchanted by the H.G. Wells short story “The Country of the Blind,” set in an isolated society where blindness prevailed for three centuries and where a lost Western traveller finds himself the aberrant one, afflicted with sight. Drawing on the Wells story, his own childhood experience of visual migraines that temporarily blunted his color perception, and his neurological work with a painter who had suddenly become colorblind, Dr. Sacks bridged two of his great literary and intellectual heroes — Wells and Darwin — and wondered whether there might exist, not in fiction but in geography, a real isolated culture where total colorblindness — or achromatopsia — had become a basic condition among the population.

Because such mutations are most easily contained in cultures isolated by sea, he reasoned that if such a society existed, it would have to be on an island. After tracking down the appropriate colleague to ask, he was surprised and thrilled to learn that one such island did indeed exist — Pingelap in the Caroline archipelago of Micronesia, where total colorblindness had been coloring the genetic pool for two centuries.

In 1993, tantalized by the promise of a real world that seemed fetched from his fancy, Dr. Sacks set out for Micronesia on a journey “not part of any program or agenda, not intended to prove or disprove any thesis, but simply to observe.” He recorded these observations in The Island of the Colorblind (public library), where they became, like all of his work at the intersection of science and literature, something much larger and richer than mere record — a wellspring of profound and poetic insight into the most central truths of the human experience gleaned from its most unusual and often stigmatized peripheries.

Like all genetic deviations from the mean, colorblindness on Pingelap had emerged due to a formidable brush with randomness. In 1775, a typhoon decimated 90% of the people living on the island. Most of the remaining survivors eventually succumbed to a slow death of starvation, so that of the one thousand islanders only twenty remained. Several centuries earlier, the original settlers had brought to Pingelap the recessive gene for colorblindness, but because the population had been large enough, the odds of two carriers marrying and the gene manifesting in their children had been fairly low. Now, with a tiny but fertile group left with no recourse but inbreeding to repopulate the island, the recessive gene suddenly flourished into growing domination and total colorblindness was soon a common condition.

When achromatopsia first appeared on Pingelap, the term maskun — local for “not-see” — was coined to refer to those afflicted. Two hundred years after the fateful typhoon, 57 of the 700 islanders were maskuns and an entire third of the population carried the gene for the condition. Total colorblindness manifested in one out of every twelve people — a gargantuan leap from the one in 30,000 precedence everywhere else in the world.

Dr. Sacks paints the unusual genetic backdrop against which this little-studied and therefore poorly understood culture plays out:

Colorblindness had existed on both Fuur and Pingelap for a century or more, and though both islands had been the subject of extensive genetic studies, there had been no human (so to speak, Wellsian) explorations of them, of what it might be like to be an achromatope in an achromatopic community — to be not only totally colorblind oneself, but to have, perhaps, colorblind parents and grandparents, neighbors and teachers, to be part of a culture where the entire concept of color might be missing, but where, instead, other forms of perception, of attention, might be amplified in compensation. I had a vision, only half fantastic, of an entire achromatopic culture with its own singular tastes, arts, cooking, and clothing — a culture where the sensorium, the imagination, took quite different forms from our own, and where “color” was so totally devoid of referents or meaning that there were no color names, no color metaphors, no language to express it; but (perhaps) a heightened language for the subtlest variations of texture and tone, all that the rest of us dismiss as “grey.”

When he hears of a vision researcher at the University of Oslo named Knut Nordby — a physiologist and psychophysicist who had made his personal condition, colorblindness, the area of his professional expertise — Dr. Sacks immediately knows that his Norwegian colleague would be the perfect companion for a trip to the curious island of the colorblind. The go went on to “form a team, an expedition at once neurological, scientific, and romantic,” and depart for the archipelago harboring the mysterious island.

Dr. Sacks soon finds that his colorblind colleague reaps the rewards of the visual world as much as, if differently from, the color-seeing majority. He writes of their arrival:

For us, as color-normals, it was at first just a confusion of greens, whereas to Knut it was a polyphony of brightnesses, tonalities, shapes, and textures, easily identified and distinguished from each other.

Indeed, Dr. Sacks and his companions discover that maskuns, especially maskun children, have adapted to and compensated for their condition in remarkable ways. Observing a group of schoolchildren, he writes:

The achromatopic children seemed to have developed very acute auditory and factual memories… [They] were oddly knowledgeable too about the colors of people’s clothing, and various objects around them — and often seemed to know what colors “went” with what… We could already observe in these achromatopic children in Mand how a sort of theoretical knowledge and know-how, a compensatory hypertrophy of curiosity and memory, were rapidly developing in reaction to their perceptual problems. They were learning to compensate cognitively for what they could not directly perceive or comprehend.

In this wonderful excerpt from a 1998 radio interview by Henry Tischler, uncovered and animated by Blank on Blank, Dr. Sacks relays the incident that illuminated for him the way in which the maskuns had transformed their condition not into a disability but into a different ability, one superior to his “normal” ability in surprising and humbling ways — an insight that applies as much to colorblindness as it does to conditions like autism:

There is a sort of critical level, so that if a tenth or a quarter of the population have some condition, it has to be accepted as a legitimate form of life and won’t be marginalized and, sometimes, won’t even be noticed.

The Island of the Colorblind is a revelatory read in its totality. Complement it with Dr. Sacks on death and destiny, the power of music, choosing empathy over vengeance, and his stirring recollection of his largehearted life, then revisit more Blank on Blank animated archival treasures: Leonard Cohen on creativity and his influences, Nora Ephron on women and politics, Kurt Vonnegut on what it takes to be a writer, Sally Ride’s conversation with Gloria Steinem about being a trailblazing female astronaut, John Lennon and Yoko Ono on the art of love, Ray Bradbury on the secret to great storytelling, David Foster Wallace on the dark side of ambition, Jane Goodall on overcoming extraordinary odds, Hunter S. Thompson on the only cure for our destructive tendencies, and Richard Feynman on what his father taught him about the most important thing.