How to read the important parameters of sunglasses? Full analysis of light transmittance, UV400, UVA/UVB penetration
ChangWilsonParameter 1: What is light transmittance (VLT)? How to check it?
Visible Light Transmission (VLT) refers to how much "visible light" the lens allows to enter the eye. According to Taiwan BSMI, based on the national standard CNS 15067 , sunglasses are divided into 0 to 4 categories, ranging from transparent lenses for indoor use to high-shield lenses suitable for strong light on snowy ground.
The following is a detailed classification table:
| Grade classification | Transmittance range | Applicable scenarios | Remark |
|---|---|---|---|
| Category 0 | More than 80% | For nighttime and indoor use, without sunshade function | Mostly clear or slightly tinted lenses |
| Category 1 | 43% ~ 80% | In cloudy and low-light environments, glare can be slightly reduced | Transitional use between indoor and outdoor |
| Category 2 | 18% ~ 43% | Daily outdoor activities, general driving, basic sun protection | The most common outdoor sports and daily models |
| Category 3 | 8% ~ 18% | In strong sunlight, such as at the beach, on the golf course, or on mountain climbing | Specially designed for outdoor strong light, with excellent sunshade |
| Category 4 | 3% ~ 8% | It is not recommended to use it while driving in extremely strong sunlight environments, such as snow, deserts, and mountains. | Can cause dim vision, not suitable for nighttime and driving use |
The entire series of GoPlayer® sunglasses use CAT.3 filters , which are suitable for strong light environments such as the beach, golf courses, and high-speed cycling. They can significantly reduce glare interference without losing color recognition, and are the gold grade for sports sunglasses.
Parameter 2: What does UV400 mean? Does dark color protect against the sun?
UV400 is an internationally accepted UV protection standard, which means that the lens can effectively block the UV band from 280nm to 400nm , covering UVA, UVB and even UVC . However, it should be noted that the color depth of the lens has no direct relationship with whether it is UV-proof .
The following is the official certification standard of Taiwan BSMI for UV400:
| project | BSMI certification standard (CNS 15067) |
|---|---|
| UV shielding range | Need to block wavelength 280nm-400nm (including UVA and UVB) |
| UVA Transmission Limit | No higher than 5% (i.e. more than 95% of UVA must be blocked) |
| UVB Transmission Limit | No higher than 1% (i.e. more than 99% of UVB must be blocked) |
| Valid marking conditions | Must be marked with UV400 and the lens filter level and manufacturer information |
| Common labeling terms | UV400, 100% UV Protection, Anti-UV, Anti-UV, etc. all need to be verified by actual measurement |
| Effect of lens tinting | Dark lenses do not mean high protection, and they must be tested to confirm their UV blocking ability |
For example, dark lenses without a light-filtering coating or coating will dilate the pupil and further absorb more UV rays.
All GoPlayer® lenses have passed UV400 testing and have an additional REVO coating to enhance the light-shielding effect .
- UVA penetration rate: only 0.397%
- UVB penetration: 0%
This means that GoPlayer® lenses are far superior to the BSMI standard (UVA ≤ 5%, UVB ≤ 1%) and truly provide full-band UV protection.
Parameter 3: What is the optical grade? Why does it affect the comfort of long-term wearing?
In addition to light transmittance and UV protection, professional sunglasses have another key data that is often overlooked: optical class .
This standard is mainly used to judge the image quality, clarity, and whether there is deformation and chromatic aberration of the lens. Especially in the case of high-speed movement or long-term wear, the optical grade will directly affect the wearer's eye fatigue, concentration and visual stability.
| Optical grade | Definition | Applicable scenarios |
|---|---|---|
| Class 1 | High-precision lenses, no distortion of visual imaging, suitable for long-term wear | High-end sports glasses, daily protective glasses, driving glasses, etc. |
| Class 2 | There is some slight deformation, which will not affect the vision in a short time | Fashion Accessories Sunglasses |
| Class 3 | Obvious distortion is visible, and long-term wearing is not recommended | Cheap or unproven products, only for short-term sun protection |
According to EN ISO 12312-1 (sunglasses standard) and Taiwan CNS 15067, the optical grade is determined based on the following quantifiable optical deviation parameters in addition to the overall visual distortion:
| Test items | Measurement instructions | Class 1 restrictions |
|---|---|---|
| Spherical Power | Deviation of the lens from the spherical image | ≤ ±0.12 D |
| Astigmatic Power | Astigmatism distortion caused by lenses | ≤ ±0.12 D |
| Prismatic Imbalance | Left-right parallax causes asynchrony of sight | ≤ 0.25 Δ |
| Power Imbalance | Difference in light transmittance between left and right lenses | ≤ 0.12 D Difference |
These items are tested with standard instruments and technical conditions, and the optical grades are classified according to the test results:
| Optical grade | Spherical/astigmatic error tolerance | Prism Deviation | Applicable instructions |
|---|---|---|---|
| Class 1 | ≤ ±0.12 D | ≤ 0.25 Δ | High-precision lenses, suitable for long-term, high-speed movement scenes |
| Class 2 | ≤ ±0.25 D | ≤ 0.50 Δ | Slight deformation, short-term wearing does not affect visual safety |
| Class 3 | ＞ ±0.25 D | ＞ 0.50 Δ | May cause visual distortion and fatigue, only for short-term sun protection |
Most sunglasses on the market only claim to have an optical grade, but it is difficult to provide specific test data. GoPlayer® sports sunglasses have passed rigorous testing and the data is better than international standards :
| Test items | GoPlayer® measured values | Class 1 Standard Upper Limit |
|---|---|---|
| Difference in spherical power between left and right filters | 0.03 | ≤ 0.12 |
| Prism Difference | 0.05 Δ | ≤ 0.25 Δ |
This means that users can obtain stable, clear vision without losing focus when moving at high speed (such as driving swings, cycling sprints) or wearing the lenses for a long time. It is not only comfortable but also effectively reduces eye pressure fatigue and dizziness.
Choosing GoPlayer® is not just about appearance, but also about choosing a pair of professional-grade sunglasses that have been professionally verified and will not cause visual burden even when worn for a long time.
To choose professional sunglasses, first understand the parameters
A pair of professional sunglasses is not just about cool looks and dark colors, but also about having real protection capabilities in terms of data. From the light filtering level (CAT classification), UV blocking ability (UV400), to the actual UVA / UVB penetration rate, each item is an indispensable standard for eye protection.
GoPlayer® series sunglasses have not only passed Taiwan BSMI certification, but also have complete data support. From materials, structure to protection effect, each pair can make you feel at ease to choose and wear. Learn more about GoPlayer® Sunglasses Series
Further reading｜More knowledge on buying sunglasses
Want to know more about lens technology, protection ratings and sports-specific designs? These useful articles will help you avoid myths and choose the right sunglasses.
- Eyes need more sun protection! The truth about outdoor sun protection that is often overlooked
- What are the differences between sports sunglasses and regular glasses? 5 key differences
- How to read Taiwan BSMI certification? Must read before buying sunglasses
- How to read the important parameters of sunglasses? Transmittance, UV400, UVA/UVB full analysis
- What is REVO coating? Why professional athletes choose it
- What is AR coating? Key technologies for anti-reflection and anti-static
- 9 most common myths when choosing sunglasses
Have a question? Or want to order custom glasses for your team/company?
Welcome to add our LINE for enquiries👉 @214ehuyt
For more information about group customization and corporate orders, please refer to our customization page 👉 GoPlayer® Group Clothing & Sunglasses Customization