When you go to an optician, people with high vision may have heard the word "Index". Have you ever wondered what Index is and how it affects our glasses? Today, Tower Optical will help you solve the mystery.
Index is the refractive index (refractive index)
of the spectacle lens. The higher the refractive index of the spectacle lens, the thinner the spectacle lens will be. In other words, it is a value that tells us how thick or thin our spectacle lenses are.
The Index starts from 1.5, 1.6, 1.67, 1.70, and 1.74. Ordinary plastic lenses that are commonly used have an Index of 1.5, which is considered a regular lens or a non-thin lens with the thickest lens. And the type of spectacle lens will start at Index 1.6.
Who should use thin lenses?
Those with high myopia or hyperopia from 350 and above, our experts will recommend using thin lenses. Because when cutting and assembling, it will make the glasses look beautiful, the lens does not overflow the frame. Until it loses the personality of the wearer.
What kind of frame and lens should I choose if I have high vision?
For those with high vision, you should choose a thick frame to support the spectacle lens. And the frame should be the right size, not too big. Because when the lens is frosted to cut and assemble, the thickest part of the lens will be frosted out completely. Which will help the lens look not too thick.