The Colorless Paradise An Examination of Color Blindness on the Island of Pingelap by Amanda King

Where in the world is Pingelap? The Pingelap Atoll is an island consisting of a circular coral reef surrounding a lagoon in the Pacific Ocean. A part of the Federated States of Micronesia, it is very small... o At its largest point, it is less that 2.5 miles wide It's sometimes known for serving as a supply base during World War I after being seized by Japan. o More importantly, it is recognized for its high population of residents who can see only in black and white Today, it has roughly residents, roughly 10% of which are affected by total color blindness - known as Achromatopsia

What is Achromatopsia? An unpreventable, incurable hereditary Disorder that results in t he total inability to see color (everything is seen in black, white, and shades of grey) o also known as "total color blindness" or "monochromacy" o called "Maskun", which means "to not see" in Pingelapese Less than 1 in 33,000 people in the US are affected (.003%). In Pingelap, 10% are affected with the disorder and 30% are unaffected carriers. o Roughly 100 times the normal percentage! Cone cells in the retina (which are needed for color vision) are absent, leaving only Rod cells – which are responsible for peripheral night vision and are very sensitive to bright light. Symptoms: o Nystagmus (involuntary eye movements) o Extreme sensitivity (even in normal daylight) o Poor visual acuity (ability to recognize fine details) o Excessive squinting is necessary to see in sunlight

What is it like to be completely color blind? Achromatopes do not perceive absense of color as "grey", because they have no prior experience with other types of colors. They have no feeling or perception of color. Perception and Total Color Blindness Normal color vision view of Pingelap Vs. Achromatopic vision: Little ability to recognize fine details, bright light is percieved as excessive, monochromatic

In 1775 a huge storm called Typhoon Liengkieki ravaged the island, leaving only 20 inhabitants (90% were killed, meaning the original population was around 200) Ruler Nahnmwarki Mwanenised was one 20 survivors and is believed to have been a carrier of Achromatopsia o Every carrier on the island can trace their ancestry back to Nahnmwarki Inbreeding was necessary to replenish the population, and in the 4 th generation of inbreeding Achromatopsia appeared o From the 4th to 6th generations, the prevalence of this disorder rose from 2.7% to about 5% - over a 2% rise! o This spike is a result of two genetic concepts: Bottleneck Effect and Genetic Drift The Bottleneck Effect: A form of genetic drift, occurs when a population reduces suddenly in size Genetic Drift: Fluctuations in allele (gene pair) prevalence in an isolated population Why is Achromatopsia so prevalent in Pingelap?

Living Color Blind on Pingelap Island The Island of the Colorblind: Prominent neurologist Oliver Sacks, along with his Achromatopic partner Knut Knordby, sets up a medical clinic to study Achromatopsia on Pingelap. He was so inspired by the villagers' accounts that he produced both a documentary and book on the subject. o Discovers that the Colorblind live mostly normal lives o In his studies, Sacks "listens to these achromatopic islanders describe their colorless world in rich terms of pattern and tone, luminance and shadow" (Google Books) Sacks asking children to distinguish colors in a still from the documentary version of "Island of the Colorblind" "I discovered that in everyday life people with Maksun are hardly distinguishable from those without – only the constant blinking of the eyes in the bright sunshine reveals any difference. " - Hannes von der Fecht Since bright sunlight greatly impairs vision, Villagers that suffer from Achromatopsia are more comfortable operating at night Overall, the Pingelap people are able to live in a colorless world because a colorless world is all they have ever known.

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