The prodromal symptom of retinal detachment is a flashing sensation in a specific area. This flashing sensation often comes from the pulling stimulus that preceded the retinal detachment. The presence of a flash indicates that the corresponding retinal area is at risk or likely to develop a retinal tear. An early symptom of retinal detachment is an increase in the number of flying mosquitoes in front of the eyes, or even a floating black shadow in front of the eyes. The detached retina may appear obscured in the corresponding area, as retinal fissures often occur in the periphery, so the detached retina progresses from the periphery to the center. As the retinal detachment expands, the occlusion will gradually enlarge. When the retinal detachment involves the macular area, the visual acuity will be significantly reduced, even to below 0.1. If the retinal fissure occurs in the macular area, the visual acuity will be significantly reduced before the retinal detachment. Significant deficits in the central visual field may occur.