What’s the difference between cheap lenses costing tens of dollars and lenses costing hundreds or thousands?

After talking about sunglasses and photochromic glasses before, these are some important sales products in the eyewear industry. So now let’s talk about the most important part of a pair of glasses – the lenses.

Generally speaking, eyeglass lenses can be divided into two categories, namely glass lenses and optical resin lenses.

Glass lenses actually appear very rarely now. Before the emergence of resin lenses, glass lenses were widely used for their high hardness and good wear resistance, and their quality and parameters will not change over time. And change. However, the impact resistance (not resistant to falling, fragile) and weight of glass lenses are far inferior to those of resin lenses.

Resin lenses are generally much lighter than glass lenses, and have better impact resistance than glass lenses, but their surface hardness is lower and they are easier to be scratched. Resin lenses and coated lenses are soft due to their soft characteristics, so you should be careful not to let the mirror surface directly contact hard objects. When scrubbing, it is best to clean it with clean water (or mixed with a small amount of detergent), and then use a special test cloth or high-quality tissue paper Blot water droplets from your spectacle lenses. In addition, in places with poor environmental conditions (such as construction sites, or places with strong wind and sand, try to use lenses with better wear resistance), and you should be careful when using coated lenses to avoid being stained with dirt and difficult to clean.

In addition to cheap glass lenses, resin lenses are also divided into good and bad. For example, many friends always think that glasses are huge profits when they buy glasses, so they bargain hard, and you end up with lenses priced at 700 to 800 yuan. Don't be secretly proud that you won two or three hundred after a counter-offer. Because in order to avoid losing customers, some businesses will secretly replace your lenses. The most common one is to replace them with ordinary spherical lenses instead of better aspherical lenses. So, what is the difference between the two. A picture will tell you simply.

Secondly, aspheric lenses are divided into different grades according to their refractive index. Refractive index 11.49 1.51 1.56 1.60 1.67 1.71 1.74 and so on. Generally speaking, the higher the refractive index, the more expensive the lens is, because most high-refractive index lenses are made of MR-8 material, which has high light transmittance and better processing toughness. Generally speaking, the higher the power, you should use lenses with a high refractive index. For lenses above 600 degrees, you should at least use lenses with a refractive index of 1.60 or above. Of course, this also depends on personal economic conditions.

As for the price of various lenses that everyone is concerned about, I will take a special article to describe it in the future to prevent everyone from being deceived. Welcome to follow me! ! !