The Light–Eye–Brain Axis: Neurobiological Links Between Mood Disorders and Myopia—A Narrative Review

Light is a major environmental signal that shapes circadian rhythms, mood regulation, and ocular growth through a network of non-visual photoreceptive pathways. Increasing evidence suggests that photic information, particularly as decoded by intrinsically photosensitive retinal ganglion cells (ipRGCs), converges on central circuits governing both affective states and refractive development. To integrate these cross-system interactions, we propose the conceptual framework of a "light-eye-brain axis," which outlines how environmental light cues are encoded by the retina and subsequently modulate neuroendocrine, autonomic, and inflammatory processes. Within this framework, mood disturbances may contribute to myopic progression through altered light-exposure behaviors, neurotransmitter imbalance, hypothalamic-pituitary-adrenal axis instability, and impaired neuroplasticity, whereas high myopia may increase vulnerability to anxiety or depressive symptoms through shared neural and immune pathways. Taken together, this integrative perspective highlights how light-dependent signaling shapes both emotional and refractive outcomes, and provides a conceptual foundation for future mechanistic studies as well as evidence-informed approaches to optimizing light exposure in the context of mood and visual health.