As a teenager experimenting with psychedelics, Ed Prideaux had no inkling that his trips would stay with him for the rest of his life. But days after his final LSD trip, when he was still experiencing melting walls and tunnel vision, he knew something wasn't right. In this episode of the Third Wave podcast, Ed talks with Paul F. Austin about Hallucinogen Persisting Perception Disorder (HPPD), what life is like for those who have this condition, and what factors may contribute to the risk of developing it.