You hear these numbers a lot. What do they mean?

Students with high myopia often hear such a sentence: "Your degree is a little high, do you need to upgrade the lens to 1.67?" Otherwise the eyeglass online will come out too thick."

The above mentioned 1.67 refers to the refractive index of the lens. At present, the refractive index of the lens is mainly divided into 1.56, 1.61, 1.67, 1.71, 1.74 and other specifications. The larger the number, the larger the refractive index, the thinner the lens edge, and the more expensive the price.

Why is it that the higher the degree, the guide will advise you to match a larger refractive index lens? Because the higher the degree, the thicker the corresponding lens edge under the same refractive index.

Therefore, if you want to wear thin glasses, you can choose a lens with a higher refractive index.

Refractive index selection reference:

1.56:0-300°

1.61:300 °-600°

1.67:600°-900°

1.74: Above 900°

After reading the parameters of the frame and the lens, we can also make the final choice according to the function of the lens. The main functions of the lens are anti-blue light, discoloration, anti-fog and so on.

Anti-blue lens

It filters out the blue radiation emitted by electronic devices such as mobile phones and computers. Anti-blue lenses can reduce the fatigue of glasses to a certain extent and avoid further deepening of the degree.

Color-changing lens

Refers to the normal transparency in the indoor, outdoor into a certain color of the lens, can achieve the effect of sunglasses in the outdoor, a pair of glasses play two roles, convenient summer use.

Anti-fog lens

It is mainly designed for the convenience of entering the indoor lens in winter without fog.

You can choose different types of glasses according to your needs.

The old glasses are not good, they need to be replaced

Friends who wear glasses also need to pay attention to: due to different individuals and glasses materials, the cycle of replacing glasses is not absolutely fixed.

We should go to the hospital regularly and replace the glasses according to our own situation, which is particularly important for the growing population. Here are some suggestions:

childhood

Children in childhood are young and their eyes change quickly, so they must be reviewed once every six months to a year, and the degree change of more than 50 degrees should be replaced in time.

boyhood

Teenage children are at the peak of development, and is the "golden age" of learning, and need to be reviewed every year.

youth

In this period, the body of the population has gradually matured, the eye degree has become stable, and the general review is 1 to 2 years.

After 30 years old

After getting older, some people will begin to suffer from eye fatigue or discomfort due to busy work, and they need to have regular eye examinations, at least every 2 years, and consider whether to replace lenses according to the condition of eye vision.

Finally, I wish you can use your eyes scientifically, take off your glasses as soon as possible, and free our noses and ears