Currently, factories classify lenses into two grades: Grade A and Grade B. Our company just produces only Grade A lenses. So how do you determine if the lenses you purchase are good quality( Grade A lenses)?
First, let’s look at the areas of the lens: Lenses typically have three areas: A, B, and C.
Area A is a 30mm diameter circle centered on the lens’s center, as shown in the white area in the image below.
Area C is the 5mm ring around the lens edge, as shown in the blue area in the image below.
Area B is the area between Area A and Area C, which is the yellow area in the image below.
Currently, there are four main standards used by various manufacturers to distinguish Grade A lenses:
1. Location, Size, and Quantity of impurities
Impressions typically refer to air bubbles or impurities produced during lens manufacturing. For Grade A lenses, there should be no impurities within 5mm of the center in Area A; and no more than one impurity smaller than 0.1mm in other areas of A area. no more than two impurities smaller than 0.2mm in Area B; and no more than four impurities smaller than 0.2mm in Area C. If the number and location of impurities exceed these limits, the lens does not meet the Grade A standard.
It should be noted that all lenses produced in all factories will inevitably contain some impurities during the manufacturing process.Therefore, as long as the number, size, and location of the impurities meet the standards for Grade A lenses, they will not interfere with the use of the lenses. They are even difficult to see with the naked eye, so you don’t need to worry about them. However, if the lenses you purchase do not meet the above conditions, you need to consider whether you have bought Grade A lenses.
2. Scratches
The smoothness of the lens surface is a key factor in evaluating lens quality, as it affects both the lens’s appearance and the user experience. Grade A lenses are not allowed scratches in Zone A (the visual center area); scratches in this area will affect the normal use of the lens. Zones B and C allow fewer than 1 minor scratch not exceeding 2 mm. However, these scratches usually disappear during rotation and are not visible when viewed from different angles, therefore they will not affect the user’s vision.
To meet this standard, workers typically wear gloves throughout the production process to prevent scratches on the lenses. After production, the lenses are individually packaged to prevent scratches during handling. Furthermore, the quality control department conducts rigorous inspections before shipping to ensure the lenses meet the quality standards for Grade A lenses. This is a key aspect of the factory’s quality control.
3. Edge Defects (Foam/Fragile Edges /Adhesive Film)
Besides surface defects, the presence of edge defects determines whether a lens meets quality standards. Grade A lenses are not allowed any defects in Zones A and B, including foam, edge fragments, and film. In Zone C, one defect smaller than 2 millimeters is permitted, which will not affect the user experience.
4. Significant Defects (Small Spots/Acne-like Marks)
For Grade A lenses, any large small spots or pimple-like marks are unacceptable; their presence indicates a substandard product.
Grade A lens quality standard：
These are the current industry standards for distinguishing lens quality. Now you know how to determine if a lens is a qualified Grade A lens. If you would like to learn more, please contact us for more information on high-quality blue light blocking lenses, transition lenses, and photochromic blue blocking lenses.
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