Anticipatory grief and existential darkness in bilateral vision loss from intraocular metastasis: A review

Intraocular and optic pathway metastases constitute rare but profoundly disruptive manifestations of advanced cancer, often leading to rapid and irreversible bilateral vision loss. Although the ophthalmic literature extensively documents tumor behavior and treatment outcomes, the psychological and existential implications of impending blindness remain largely unexamined. This narrative review synthesizes evidence across oncology, vision-loss psychology, and grief studies to conceptualize the phenomenon of existential darkness, defined as the convergence of sensory extinction, identity disruption, anticipatory grief, and existential fear experienced as patients confront the loss of sight within a terminal prognosis. The clinical trajectory of ocular metastasis characterized by abrupt decline, limited survival, and high bilateral risk creates a compressed period in which psychological adaptation becomes extraordinarily challenging. Patients frequently experience despair, meaning collapse, relational disconnection, and heightened death anxiety, yet psychosocial frameworks specific to vision-threatening metastasis are absent. Integrating meaning-centered psychotherapy with early low-vision rehabilitation emerges as a promising, though untested, strategy to support agency, coherence, and dignity during visual decline. By articulating existential darkness as a distinct psycho-oncological construct, this review identifies critical gaps and outlines a foundation for clinical and research efforts that address the profound human experience of losing the visible world at the end of life.