40 Hz light flicker stimulation for neurodegenerative diseases: Mechanisms and clinical perspectives.

Neurodegenerative diseases are a class of disorders characterized by the progressive degeneration and dysfunction of neurons, such as Alzheimer's disease (AD) and Parkinson's disease (PD). Due to their high incidence rate, irreversible pathological processes and huge social and economic burdens, these diseases have become a major challenge in global public health. Light Flicker Stimulation (LFS), as a non-invasive form of physical therapy, shows significant neuroprotective potential by modulating electrical brain oscillations and particular signaling pathways. We critically examine the role of stimulation parameters (frequency, wavelength, multisensory combination) and discuss the state of clinical translation, including completed and ongoing trials, safety considerations, and technological innovations such as alternating bilateral stimulation and organic light-emitting diode (OLED) devices. By integrating mechanistic insights with clinical perspectives, this review aims to identify key gaps and future directions for harnessing 40 Hz LFS as a viable treatment for neurodegenerative diseases.