Interesting. Before you rush to your dealer, note that this is n=1, self-administered (albeit with self-blinding of their scores over several months), and quite a cocktail:

> The subject of this case study self-administered the Ishihara test prior to taking a large 5 g dose of psilocybin-containing mushrooms.

> Additionally, the participant in the current case study took an unusually broad range of psychoactive substances – including weekly cannabis, an LSD microdose and a blast of nasal esketamine – that may complicate interpretations of his score.