The structure of the human eye consists of three layers: the sclera, the choroid, and the retina. Retinal detachment is not actually a separation between the retina and the choroid, but rather a separation between the neural epithelial layer and the pigment epithelial layer of the retina, which means it is a detachment between the inner nine layers and the outermost layer of the retina. Retinal detachment can be classified into three types: rhegmatogenous retinal detachment, which is mainly caused by a tear in the retina allowing the vitreous fluid to enter the subretinal space; tractional retinal detachment, which occurs due to vitreous and retinal proliferation exerting traction on the retina, commonly seen in diabetic retinal detachment; and exudative retinal detachment, which is caused by accumulation of fluid between layers due to abnormal choroiditis.