A vision of 4.8 is a mild abnormality. Mild vision loss can be caused by a variety of reasons, with refractive errors such as nearsightedness, farsightedness, and astigmatism being the most common. The most common causes are refractive errors such as myopia, hyperopia, and astigmatism. Myopia is usually around 100 diopters, astigmatism is between 50-100 diopters, and hyperopia is around 200-300 diopters. The exact number of diopters cannot be deduced solely from the current visual acuity and can only be determined through an optometric examination. However, in addition to refractive error, there are many eye diseases that can cause slight vision loss, such as cataracts, iridocyclitis, macular degeneration, optic neuropathy, corneal opacities, etc. Patients need to be examined by an ophthalmologist at a hospital first. Patients need to undergo a detailed and comprehensive examination at the ophthalmology department of the hospital first to confirm the cause of the vision loss to 4.8.