Color blindness, or color vision deficiency (CVD), is a prevalent condition affecting approximately 300 million people worldwide. The disorder is characterized by an inability to perceive and distinguish between different colors, affecting around 8% of men and 0.5% of women. However, there may be a potential link between psychedelics like psilocybin mushrooms and the possible improvement of color blindness symptoms. Building upon anecdotal evidence from a 2017 study, recent follow-up research has further explored how psychedelics could hold the key to enhancing color vision for individuals with color blindness.
Cone cells are the specialized photoreceptor cells that are found in the retina. They play a significant role in the ability to perceive different colors. People with normal color vision have three types of cone cells: red, green, and blue. These cone cells are responsible for detecting different wavelengths of light and transmitting that info to the brain so that it can perceive a wide range of colors. When a specific color, such as green, enters the eye, the green cone cells are stimulated and generate electrical signals to the brain’s optic nerve, which processes and interprets color. The brain can perceive millions of color pigments using combined signals from different cone cells.
Those with color blindness have a genetic defect where one or more cone cells are missing or functioning incorrectly. As a result, they are unable to see certain colors most people take for granted, and in rare cases when none of the cone cells work, they may not be able to see color at all.
There are several different types of color blindness ranging from mild to severe. The most common form of color blindness is red-green color blindness which includes deuteranomaly and protanomaly. In these types, the red and green cone cells are affected, making it difficult to determine between shades of green and red. Color blindness can cause confusion and daily challenges in identifying certain objects and analyzing color-coded information such as traffic lights.
There have been several self-reported instances of individuals seeing at least a partial improvement in their color blindness after a single use of psilocybin-containing mushrooms. A 2017 study published in the journal Drug Science asked participants to report if psychedelics improved their symptoms of color blindness. Of the 47 responses that could be categorized, 23 saw an improvement in their color blindness after taking psychedelic drugs (1). The most commonly cited drugs were magic mushrooms and lysergic acid diethylamide (LSD). However, other psychedelic drugs, such as DMT and MDMA, were also reported. The responding individuals noted that the changes in their color blindness remained improved from a period of several days to years. The researchers of the study believe that the improvement of color blindness in these individuals could be because psychedelics allow certain connections in the brain between parts that process visual information and the parts to understand language. As a result, the reporting individuals had improved visual processing and could understand new colors that they previously were unable to perceive
In a new study recently published in the Journal of Drug Science, Policy and Law, a 35-year-old man’s color blindness saw lasting improvements after his use of psychedelic mushrooms (2). The man had mild deuteranomalia (red-green CVD) and a history of psychedelic use. He reported a significant improvement in his color vision after the ingestion of psychedelic shrooms. The man first took a self-administered Ishihara test to determine the baseline score of his color blindness. Scores 13 or below indicate color blindness, while scores 17 and higher indicate normal color vision. Any scores between 14 and 16 are typically rare and require more tests to determine the presence of color blindness. The subject reported a score of 14, though he also provided documentation of a diagnosis of mild color blindness from five years prior.
After the baseline test, the man consumed five grams of dried psilocybin mushrooms. Twelve hours after ingesting the mushrooms, he retook the test and scored 15. Then, 24 hours later, his score rose to 17, above the standard for normal vision. By day eight, his score peaked at 19 and remained around 18 for approximately four months. A year later, he retook the Ishihara test one more time, and he scored 16. Although the score did not qualify him for having normal color vision, it was still higher than his baseline, demonstrating an improvement in his color blindness symptoms.
Because color blindness is a genetic mutation, the changes these subjects experienced after taking psilocybin would not produce a DNA change that would fully correct the defects. Researchers are still unsure why psilocybin has shown multiple instances of improving color blindness in the many reported results they received.
Psychedelic drugs do not alter how the eyes send visual signals to the brain. Even under the influence of psychedelics, the signals sent from the retina to the primary visual cortex remain mostly the same. However, psychedelics like psilocybin can affect higher-level processing in the brain, which can ultimately change our perception of color (3). When the brain is in a psychedelic state, it becomes more flexible and forms new neural connections. These connections can link new colors with existing concepts of colors or improve color perception even for people with color blindness. Psilocybin has been shown to increase the formation of the brain networks involved in color processing, and these changes in brain chemistry could persist beyond the initial effects of the substance (4).
Though people may experience a wider range of colors under the influence of psychedelics, this doesn’t mean that the colors they see are more accurate. Individuals with color blindness still have a concept of colors, even if they are unable to distinguish them. Some of the colors experienced may be entirely new for them, though the brain can associate these new colors with objects based on their perception of linguistic ideas. As a result, they may experience changes in their awareness regarding the color of specific objects (Anthony et al. 2020).
Since the study found multiple reports of long-term changes in color blindness, there may be an indication that these effects could be common in a larger population of color-blind individuals. Of course, factors such as set and setting, dosage, and other individual traits could influence the effectiveness of these changes. Furthermore, the study had many limitations, such as the self-reported anecdotes in a smaller sample size; however, researchers plan to gather more specific data in future studies to determine whether or not psychedelics can truly improve color blindness.