Herpes zoster ophthalmicus (HZO) is a significant manifestation of varicella-zoster virus (VZV) reactivation that affects the ophthalmic branch of the trigeminal nerve. This condition presents with dermatological and ophthalmic complications, including keratitis, uveitis, and neurotrophic keratopathy, which can lead to permanent vision impairment. Understanding the epidemiology, clinical features, and treatment strategies for HZO is essential for effective management and prevention of long-term complications. Introduction of recombinant zoster vaccine has significantly reduced the incidence of HZO. This chapter provides an overview of the pathophysiology, diagnosis, treatment, and prevention of HZO, supported by recent research.