When people choose prescription eyeglasses, they are more concerned about which material of lens has a higher refractive index and thinner lenses, which are lighter and more beautiful. But when selecting prescription glasses, you should focus on the refractive index and consider the Abbe number of the lenses simultaneously.

What is Abbe number?

Abbe number is the index used to express the dispersion ability of transparent media. Generally speaking, the greater the refractive index of the medium, the more serious the dispersion, and the smaller the Abbe number; conversely, the smaller the refractive index of the medium, the less dispersion, the larger the Abbe number. Abbe number is commonly used in the lens industry and is one of the reference factors for purchasing lenses. The Abbe number of optical lens materials for the eye is generally between 30 and 60.

Therefore, when you choose a pair of prescription glasses, if you are more expecting the lenses to be comfortable and clear to wear, you must take into account the prescription values, refractive index, and Abbe number of the lenses to achieve a good match between the three, and not just pursue one aspect and ignore the other two, or it will lead to other problems.

You can find out more information about Abbe number, and more prescription lensinformation.