Possible role of biochemiluminescent photons for lysergic acid diethylamide (LSD)-induced phosphenes and visual hallucinations

Introduction

Kapócs and colleagues frame this paper in the context of renewed scientific and therapeutic interest in lysergic acid diethylamide (LSD). The introduction summarises historical use and recent epidemiological reassurance that psychedelic use is not associated with long‑term increased mental health problems, and then focuses on a specific unresolved question: how LSD produces vivid visual phenomena, including phosphenes (brief sensations of light) and complex visual hallucinations. The authors note that these visual phenomena can occur even in blind people who retain prior visual experience, which suggests cortical mechanisms in addition to retinal ones. The paper sets out to present a unified, biologically grounded hypothesis—drawing on the authors' previous work and a selection of experimental findings—that LSD‑induced phosphenes and some forms of visual hallucination may result from a transient enhancement of ultra‑weak biophotons (endogenous photon emission) within the early retinotopic visual system. The introduction positions this hypothesis as an explanation linking LSD pharmacology, glutamatergic activity, oxidative chemistry and reported neuroimaging and clinical observations of LSD’s visual effects.