For the estimated 80 million people living with glaucoma worldwide, the disease's cruelest feature is its silence — irreversible vision loss often accumulates before any clinical warning. A genomic tool now maturing into clinical practice could fundamentally change that timeline by identifying high-risk individuals years before measurable damage appears.

Polygenic risk scores (PRS) for glaucoma aggregate the cumulative effect of hundreds to thousands of common genetic variants, each individually modest, into a single quantitative risk estimate. Large-scale genome-wide association studies have revealed that adult-onset glaucomas — particularly primary open-angle glaucoma — carry substantial polygenic architecture, meaning no single gene dominates risk. When PRS are layered onto established clinical parameters such as intraocular pressure, optic disc morphology, and corneal thickness, the predictive power for both case detection and disease trajectory improves meaningfully beyond traditional screening alone. This review synthesizes the evidentiary base and maps the practical "who, what, when, and where" framework governing responsible clinical deployment.

Placing this in broader context: PRS-guided screening represents a shift from reactive ophthalmology toward genomically-informed preventive care. Unlike monogenic conditions, glaucoma PRS carry inherent statistical uncertainty — a high score elevates probability but guarantees nothing, while a low score offers no immunity. Clinicians and patients both need calibrated interpretation frameworks to avoid over-medicalization or false reassurance. Crucially, PRS trained predominantly on European-ancestry cohorts may perform poorly across diverse populations, raising genuine equity concerns as these tools enter standard practice. This review's clinical framing is timely given regulatory movements toward accrediting PRS platforms, but practitioners should treat current scores as adjunctive rather than diagnostic. For health-conscious adults with a family history of glaucoma, this signals that genomic screening conversations with ophthalmologists are increasingly grounded in actionable evidence rather than speculation.