Can magic mushrooms solve color blindness? Exploring their potential.

By Lisa Marie Basile | Fact-checked by Davi Sherman
Published March 8, 2024

Key Takeaways

  • A 35-year-old male with mild red-green color vision deficiency (or color blindness) could better distinguish between colors on a common color blindness test after self-administering psilocybin, a psychedelic extract from mushrooms.

  • While researchers aren’t sure of the exact mechanism at play, they theorize that psychedelic drugs like psilocybin increase the brain’s overall sensitivity to color signals sent from the eye’s retina.

Psilocybin has long been used for religious or spiritual purposes in some cultures. Although psilocybin, a psychedelic chemical obtained from certain types of mushrooms, has been negatively associated with the ‘hippie’ counterculture movement due to recreational use in the 1970s, drug researchers have been aware of its many therapeutic uses, including in psychiatry, pain management, and cancer treatment.[][]

For patients with color vision deficiency (CVD), or color blindness—the inability to distinguish among certain hues (often red, green, and blue)—psilocybin may hold the key to treatment, reports Drug Science, Policy and Law.[][] 

According to data published in Drug Science, Policy and Law, some patients with CVD experienced long-term improvement in color perception after using certain psychedelics, including psilocybin mushrooms. For example, the journal cites the case of a 35-year-old man with mild red-green CVD, or deuteranomaly, which causes reduced sensitivity to green light.[][]

He’d taken a baseline, self-administered Ishihara Test, a common color blindness test that quantifies the severity of color blindness. It provides a series of plates composed of mosaic dots of varying colors and sizes. Each plate contains a number or combination of lines. The test-taker tries to distinguish the correct number or correctly trace the lines.[] 

Plates 1–21 can be used to reveal a color vision defect, while plates 22–25—diagnostic plates—are used to determine the type of color blindness a patient has.[] 

After the subject completed the test, he proceeded to take five grams of dried psilocybin mushrooms. After 12 hours, he took the test again, repeating this testing process over the course of four months. He self-reported his scores.[] 

“Though the subject reported intensification of colors while under the acute effects of psilocybin, his score on plates 1–21 improved only slightly to 15 at 12 h post-administration. However, by 24 h post-mushroom administration, his score reached 18, above the cut-off of 17 required by the Ishihara Test for classification of normal color vision,” the report states. “His score peaked at 19 on day eight post-administration. At approximately four months post-mushroom administration, his score remained elevated at 18,” the researchers write.[]

The subject had other substances in his system at certain points when retaking the tests, which could have confounded the results.  For example, he smoked cannabis once weekly, took a microdose (approximately 10 micrograms) of lysergic acid diethylamide (LSD) following mushroom use on day 16, and used an unclear recreational amount of nasal esketamine about two months after the initial psilocybin mushroom usage.[] 

Over a year—436 days—after the initial mushroom usage, the subject scored 16 on the plates 1–21 of the Ishihara Test. It’s important to note that the subject took four grams of psilocybin mushrooms four months prior to this test.[]

“Interpretation of durability of effect is also complicated by the fact that the subject reported taking a microdose of LSD after Ishihara Test self-administration on day 16 post-psilocybin and using psilocybin again approximately four months prior to the Ishihara Test we administered,” the researchers explain.[] “Our subject…experienced a quantifiable partial improvement in his CVD lasting for at least sixteen days, which led to reclassification of mild color-blindness to normal color vision according to self-administered Ishihara Test,” the researchers summarize.[]

How does psilocybin work to enhance color perception? According to Molecules, psilocybin’s effects can be broken down into four categories. In addition to emotional processing, cognition, and “ego dissolution,” it impacts perception. It’s this final category that may hold the key to impacting CVD.[]

The researchers say that the mechanism behind CVD improvement through psilocybin use remains unclear, although there are hypotheses. “[T]he brain can alter experience of color beyond optic nerve input…alterations in higher-level visual processing induced by psychedelics likely underly [sic] their ability to improve CVD in some individuals,” the authors write.

According to David Feifel, MD, PhD, Professor Emeritus of Psychiatry at UC San Diego and the head of Kadima Neuropsychiatry Institute, which studies various psychedelic drugs as mental health treatments, “Many people with normal color vision report increased vividness of colors during a psychedelic drug–induced ‘trip.’ Sometimes that enhanced vividness can persist long afterwards,” he says.

“Since the brain translates light signals from the eye’s retina into the perception of color, it’s possible that psychedelic drugs increase the brain’s overall sensitivity to color signals sent from the retina of the eye. If so, that increased brain sensitivity may offset the weakened signal of certain colors that are sent from the retinas of color blind people to their brains,” says Dr. Feifel.

Specifically, the researchers note that, “Psilocybin appears to increase the amplitude of visual evoked P1 potential in the lower-level processing areas of the visual pathway in the occipital cortex, which has been shown to reflect increased activity in early visual area V1. This phenomenon may be the neural correlate of psychedelic-induced increases in brightness perception.”[]

They also note that they are not aware of studies exploring psilocybin's effects on “higher order visual processing areas in the occipital cortex, such as the V4 region, which is central to color perception.”[] 

Dr. Feifel says that it’s important for researchers to scientifically validate these findings. “So far, all the evidence of improvement in color blindness, including this case report, comes from the self-reports of color blind people who have taken psychedelics,” he says. “If these self-reports do get scientifically verified, it will be very remarkable to have a single dose of a psychedelic, or any drug for that matter, produce long-lasting improvements in color blindness.”

Ryan S. Sultan, MD, an adult and pediatric mental health physician, Medical Director of Integrative Psych, and a professor of clinical psychiatry at Columbia University’s Vagelos College of Physicians and Surgeons, says clinicians should be aware of legalities associated with psilocybin use. “It is Schedule I per the Drug Enforcement Administration,” he says. “[Psilocybin] is listed as having no medical benefits, [so] you can’t get it from a doctor. There are no official supply chains.”

Dr. Sultan says that research on psychedelics is still in its infancy, and that findings like these are exciting. That said, “significantly more research [is needed] to confirm this case report's findings, gauge their generalizability, and determine the mechanism of action,” he adds.

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