The composition of the price, in terms of pricing science mainly includes, production costs, operating costs, labor required for processing and management costs, research and development costs, transportation costs, and related taxes. In this way, it seems that in the case of eyeglasses, for example, we look at the difference between being in a brick-and-mortar store and being in a Taobao store.
Nearsightedness glasses have a preventive effect on comorbidities caused by high myopia, such as retinal detachment, vitreous clouding, cataracts, glaucoma and nystagmus. Myopia glasses are concave lenses. The image made by concave lenses is always smaller than the object, upright virtual image, concave lenses are mainly used to correct myopia.
Glasses degree: The refractive strength of eyeglass lenses is generally expressed in degrees. A dioptre (dioptre), equivalent to the average person or optician said 100 degrees, that is, in non-Chinese-speaking countries D 1.00 (here the D for Dioptre rather than "degrees" Degree). The more severe the vision problem, the deeper the lens prescription and the higher the lens thickness.