Improved colour blindness symptoms associated with recreational psychedelic use


It is well documented that psychedelic drugs can have a profound effect on colour perception. After previous research involving psychedelic drug ingestion, several participants had written to the authors describing how symptoms of their colour blindness had improved. The Global Drugs Survey runs the world’s largest annual online drug survey. In the Global Drugs Survey 2017, participants reporting the use of lysergic acid diethylamide or psilocybin in the last 12 months were asked:

We have received reports from some people with colour-blindness that this improves after they use psychedelics. If you have experienced such an effect can you please describe it in the box below, say what drug you took and how long the effect lasted?

We received 47 responses that could be usefully categorised of which 23 described improved colour blindness. Commonly cited drugs were LSD and psilocybin; however, several other psychedelic compounds were also listed. Some respondents cited that the changes in colour blindness persisted, from a period of several days to years. Improved colour blindness may be a result of new photisms experienced in the psychedelic state aligning with pre-existing concepts of colour to be ascribed a label. Connections between visual and linguistic cortical areas may be enhanced due to disorder in the brain’s neural connections induced by psychedelics allowing these new photisms and concepts to become linked. This paper provides preliminary data regarding improved colour blindness accompanying recreational psychedelic use which may be further investigated in future iterations of the Global Drugs Survey or in a stand-alone Global Drugs Survey-managed psychedelics survey.

This research was published in the Drug Science, Policy and Law Journal the definitive source of evidence-based information and comment for academics, scientists, policymakers, frontline workers and the general public on drugs and related issues

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