0.4 How many degrees of myopia?

Vision is divided into central vision and peripheral vision, central vision is divided into distance vision and near vision, is the main sign of form vision, is the ability to distinguish the shape and size of two-dimensional objects, represents the visual acuity of the fovea of the retina, glasses power is diopter, vision standard is 1.0, below 1.0 is low vision. There is no direct relationship between the number of naked eye vision and myopia degree, and conversion cannot be carried out. Therefore, myopia degree cannot be judged according to the number of vision. It is necessary to go to the hospital for mydriasis optometry examination, and then detect visual function under cycloplegia to judge what kind of refractive error is, and give correct correction.