Acute retinal necrosis syndrome is a severe uveitis with retinal arteritis, massive peripheral exudate, retinal necrosis, highly cloudy vitreous, and later retinal fissures and retinal detachment. The cause is mostly due to herpes virus infection, which can occur at any age and is more common in adults. The onset is usually insidious and can be divided into an acute inflammatory phase, a remission phase, and a concurrent retinal detachment phase. The acute inflammatory phase may present with eye redness and pain, decreased vision, and dark shadows in front of the eyes. Signs in the anterior segment of the eye include moderate ciliary congestion, dusty or sheepish KP, large amounts of floaters in the anterior chamber, and high intraocular pressure may occur. The posterior segment of the eye may have mild to moderate vitreous dust clouding in the early stages, which may progress to significant vitreous clouding with fibrosis and yellowish-white infiltrative edematous lesions in the mid-peripheral retina, which may fuse from patchy and advance toward the posterior pole. The retinal vasculature is inflammatory, with arteriovenous involvement, predominantly arteritis, with thinning of arteries with white sheaths and occlusion of small branches, and yellowish-white infiltrates in the arterial walls in a segmental pattern. One month after the onset of the disease, it enters remission, the inflammation gradually subsides, the arterial vessels are occluded, and the retinal choroid is atrophied. In the later stage, the necrotic area often forms multiple retinal fissures and eventually causes retinal detachment. The diagnosis is based on clinical manifestations and laboratory serum virus antibody measurements. In terms of treatment, systemic and local antiviral therapy is required first, and systemic anticoagulation, nutrition, and absorption promotion therapy are given. In remission, laser photocoagulation can be performed to prevent retinal detachment and proliferation. In case of retinal detachment and vitreoretinal proliferation retraction, vitrectomy is required.