1. Protection Capacity
When choosing sunglasses, the primary consideration is their UV protection capability. Ensure the sunglasses block over 99% of UV rays and have a UV400 label. The UV400 label indicates that the lenses block all light with wavelengths less than or equal to 400 nanometers (nm), including UVA and UVB.
2. Filter Coefficient
The filter coefficient of sunglasses refers to their ability to absorb light. Generally, the higher the filter coefficient, the stronger the light absorption, making it suitable for outdoor environments with strong glare. Sunglasses filter coefficients are typically graded from 0 to 4, with 0 being the lowest and 4 the highest. Generally, sunglasses used in daily life have a filter coefficient of 2 or 3.
3. Lens Color
Different lens colors, while filtering light, also have different effects on vision. Common lens colors include gray, brown, green, and yellow.
Gray lenses: Suitable for most occasions, the lens has no significant impact on color perception and is suitable for extended wear.
Brown lenses: Suitable for outdoor enthusiasts, enhancing the perception of green and increasing contrast, ideal for wearing in bright sunlight.
Green lenses: Suitable for water activities, enhancing the perception of red and yellow, making colors more realistic, ideal for use at the beach or while fishing.
Yellow lenses: Suitable for foggy days, enhancing the perception of blue and increasing contrast.
Structure and Size: Choose the appropriate sunglasses structure and size according to your face shape to ensure the frame fits your facial contours. Adjustable nose pads and temple length also improve wearing comfort.
