A pair of lenses suitable for yourself should be comprehensively considered in combination with our degree, pupil distance, frame shape, budget, use scenario and other factors.
The refractive index is like the shoe size. Regardless of the brand, these are the common parameters, which can be popularly understood as the thickness of the lens. The higher the refractive index, the thinner the lens. The same 500 degree myopia, the 1.61 lens is 1.56 thin.
Although the higher the refractive index is, the thinner it is. Generally speaking, the higher the refractive index is, the lower the Abbe number is. Select the appropriate degree for yourself
Different refractive indexes have different Abbe numbers. The following are Abbe numbers corresponding to different refractive indexes:
1.50
Abbe number 58
The extremely high Abbe number is close to the visual experience of the naked eye. The spherical lens will be very thick if the degree is high. It is only suitable for low-degree myopia within 250 degrees. The base curve is large, and it is not suitable for large-frame glasses.
1.56
Abbe number 35-41
The Abbe number is moderate, 1.56 is the lowest refractive index of most lens brands, which is cheap and suitable for myopia within 300 degrees; Not recommended if the temperature exceeds 350 degrees. The lens will be thicker when the degree is higher.
1.60
Abbe number 33-40
1.60 and 1.61 are different writing habits with the same refractive index. There is no difference. According to different brands and series, the number of Abbe varies from 33-40. For example, the radiation protection of the bright moon 1.60 is 33 dB, and the PMC series of the bright moon is 40 dB.
1.67
Abbe number 32
Low Abbe number, large dispersion and general imaging effect. In the range of 550-800 degree myopia, 1.61 is too thick, the budget is limited, and it is not more than 1.71, so 1.67 is a compromise choice.
1.71
Abbe number 37
Generally speaking, the higher the refractive index of the lens, the lower the Abbe number and the greater the dispersion. However, with the breakthrough of lens material technology, this rule is being broken. For example, 1.71 is thinner than 1.67, and the Abbe number is higher.
1.74
Abbe number 33
The most refractive index and Abbe number of the resin lens are low, and the price is relatively high. However, for high myopia, there is no other choice. After all, the thickness is always the most intuitive experience. Above 800 degrees can be considered, and more than 1000 degrees can be considered without thinking of anything else. Just match 1.74.
Post time: Mar-09-2023