The cost proportion of good resin lens materials is very low! The main cost is on the eyeglasses online cheap film layer! So how expensive lenses can be sold depends on the film, because the materials are the same, and how cheap lenses can be sold depends on the raw materials.
If the plastic sheet made from the substrate is directly used to make lenses, it will be unqualified, so it needs to be coated to enhance various properties.
The first layer on top of the substrate is hardened, which is mainly aimed at protecting the substrate from scratches and the like because both polyurethane and acrylic materials themselves are not very hard.
Add an anti-reflection film on top of the hardness! The high-tech AR anti-reflection and anti-reflection film is first used on the lens. The conductive film is anti-static, and this layer is anti-dust. The top film is a composite film with anti-wear, water-resistant, anti-fog, or more functions. The anti-wear and water-resistant film made by OEM is quite good.
The most important aspect of cheap eyeglasses near me is determining the appropriate degree of myopia. Our optometry principle is the clearest state with the lowest degree. That is to say, the focal point of myopic eyes is moved back to the retina with myopic lenses to obtain a clear image.
The most common method is to determine whether it falls exactly on the retina based on the different wavelengths of red and green. Present the red and green test labels, looking at them with one eye, whether the numbers inside the green or the red are clearer. Check the visual function, and optimize the prescription according to the situation.
