Near-Infrared and Red-Light Photobiomodulation for Ocular Aging and Diseases: A Narrative Review

Near-infrared (NIR) and red light photobiomodulation (PBM) has gained increasing interest as a non-invasive therapeutic approach for a variety of medical conditions including ocular diseases. The eye represents a particularly suitable target for light-based therapies owing to its optical accessibility and the high mitochondrial demand of various tissues such as the retina and optic nerve. Ocular aging and several ophthalmic disorders are associated with mitochondrial dysfunction, oxidative stress, and chronic inflammation, providing a biological rationale for the use of PBM as a potential adjunctive approach. This narrative review provides an evidence-weighted, indication-specific synthesis of NIR and red-light PBM in ophthalmology, emphasizing device- and protocol-dependence, differences between multiwavelength PBM and repeated low-level red-light therapy, study-design limitations, safety considerations, and clinical translation gaps. A structured literature search was conducted using major scientific databases to identify relevant experimental studies, clinical trials, and observational reports. The review focuses on proposed mitochondria-centered mechanisms of action, including cytochrome c oxidase-mediated signaling, nitric oxide release, reactive oxygen species-driven hormetic responses, and downstream anti-inflammatory effects. Particular emphasis is reserved to dry age-related macular degeneration, for which literature is more relevant, and to dry eye disease owing to meibomian gland dysfunction and myopia, for which a body of evidence is progressively growing. For other ocular indications, data remain preliminary or exploratory. Overall, available data support biological plausibility and suggest possible functional or anatomical signals in selected ocular diseases, but the clinical evidence remains heterogeneous, with substantial variability in devices, wavelengths, dosimetry, treatment protocols, and study design, and remains insufficient to define PBM as established therapy for most indications. However, the clinical evidence remains heterogeneous, with substantial variability in devices, wavelengths, dosimetry, and treatment protocols. Although available studies generally report favorable short-term tolerability, long-term safety and the role of PBM in routine ophthalmic practice remain insufficiently defined. Well-designed, adequately randomized controlled trials with standardized treatment parameters are required to determine efficacy, optimal protocols, and long-term clinical relevance.