Impact of light on the human body with particular emphasis on women's reproductive health

Light exposure plays a fundamental role in human physiology, influencing circadian rhythms, hormonal regulation, and reproductive health. This review examines the multifaceted impact of natural and artificial light on women's reproductive function, with particular emphasis on mechanisms underlying light-mediated biological processes. Evidence demonstrates that light exposure affects melatonin secretion, which in turn modulates reproductive hormones including luteinizing hormone, follicle-stimulating hormone, and sex steroids. Disruption of natural light-dark cycles through shift work, artificial light at night, or circadian misalignment has been associated with menstrual irregularities, ovulatory dysfunction, reduced fertility, and adverse pregnancy outcomes. Conversely, adequate vitamin D synthesis through ultraviolet light exposure supports ovarian function and metabolic health. Recent studies reveal that continuous light exposure can induce anovulation through disruption of the leucine-mTOR-autophagy axis, while circadian rhythm disturbances correlate with polycystic ovary syndrome. This article synthesizes current knowledge on photobiological mechanisms, clinical implications, and therapeutic applications of light modulation in gynecological practice.