Pore-derived retinal detachment is relatively common and can occur at any age, but is most common in middle-aged and elderly people (with or without myopia), those with high myopia, a family history and history of ocular trauma, and those after cataract surgery. Retinal detachment is also likely to occur after dislocation of the lens due to congenital, genetic or traumatic reasons. In myopic people, especially those with high myopia, the diameter of the eye grows, making the retina stretched accordingly, and the local blood supply is poor, causing the retinal edge to become thinner and thinner, making it more prone to retinal detachment due to fissures. If myopia deepens, or if the eye is hit by external forces, or if the pressure changes dramatically, such as a sudden fall from a height (playing roller coasters and other games), diving from a high platform, riding in a car with excessive bumps, or being hit by a ball or racket when playing badminton or tennis, the retinal fissure will easily occur, followed by retinal detachment. In some people, retinal detachment can occur even without any obvious cause.