Many people do not understand why other people's glasses look good light and thin, while their glasses lenses are thick and heavy; wearing them in the eyes of others is a nerd. Some people say to choose high refractive index prescription lenses, others say to polish off the edges of the lenses, and others say to adjust the pupillary distance, so what is the best choice? What are the factors that cause thick lens glasses again?
A. Your prescription
The level of prescription is a significant factor in the thickness of the lens; more precisely, the strong the prescription, the thicker the edge or central part of the lens. Generally speaking, nearsighted lenses are thin in the middle and thick at the edges, and reading lenses are thin at the edges and thick in the middle.
B. Lens index
The lower the index of the lens, the thicker the lens; the higher the lens index, the thinner the lens when with the same prescription. But please note that all the thicknesses here are for the lenses as a whole, that is to say finished lenses that are round or oval, and when they are cut into the shape of the lenses that need to be fitted to the frame, the thickness will be different because of the differences in the individual parameters.
C. Frame size
The size of the frame is one of the main reasons for the thickness of the lenses; for nearsighted glasses, the middle of the lens is thin, and the edge is thick. The larger the frame, the thicker the lens will be cut in, so the thick lens glasses will appear.
D. Pupillary Distance
The difference between the pupillary distance and the frame center distance is what we should say here. Pupillary distance is the straight line distance between the center of the pupil of each person's left and right eye; frame center distance is the straight line distance between the center of the frame of the left and right eye of the eyeglass frame. The more significant the difference between the pupil distance and the frame center distance, the more displacement is needed when cutting the lenses. The thicker part of the lenses are cut in, the more the lenses are naturally thicker! Here is a reference value for you: the lens width of the eyeglass frame plus the nose bridge width minus your pupil distance within 3 mm is the best.
E. Types of lenses
Photochromic, polarized, and tint lenses are thicker than similar ordinary lenses. This is because photochromic lenses are generally thicker in the center to avoid light colors in the center and dark colors in the edges after the color change. Polarized lenses are also thicker than ordinary lenses because they have a selenocrystalline polarized layer in the middle. Tinted lenses are also thicker than normal lenses because they require high-temperature coloring to avoid dioptric changes in the lenses at high temperatures. The refractive index of the lenses has a certain relationship with the thickness of the lenses, but to a greater extent, it is related to their prescription. If the higher the prescription of your eyes, then the relative refractive index of the lenses will be lower, and the thickness of the lenses will be thicker,the thick lens glasses appear again. So it is recommended to choose a high refractive index.
If your prescription is strong, then when buying glasses, you need to communicate with the seller exactly what kind of standard you can achieve and whether the final thick lens glasses you can accept so that there is a mental expectation.
When choosing eyeglass frames for high prescription, try to select the ones that are smaller and thicker, such as acetate glasses or horn rimmed glasses. Thick eyeglass frames can block the thickness of the lenses and can visually reduce the heaviness of lenses. Try to choose something other than large and slim eyeglass frames, which will magnify the thickness of the lenses.