Sun protection lenses: understanding UV400, categories and materials

At Vision Janine, all our vintage glasses are equipped with lenses offering UV400 protection, the highest standard against ultraviolet rays. But what exactly does this mean, and how do you choose between the different categories and types of lenses?

What is UV400 protection?

Ultraviolet (UV) rays, invisible to the naked eye, are particularly harmful to visual health. The UV400 standard corresponds to the highest level of protection: it blocks all UVA and UVB rays up to a wavelength of 400 nanometers.

This means that your eyes are 100% protected from UV rays , regardless of the light intensity. Contrary to popular belief, it is not the darker or lighter tint of the lens that guarantees safety, but rather the presence of the UV400 standard.

But then what does the category of solar glass correspond to?

The category does not measure UV protection (always guaranteed in UV400), but the intensity of filtering of visible light and therefore comfort in the face of glare:

Category 0

Very clear lenses, light visual comfort, suitable for indoor environments.

Category 1

Lightly tinted lenses, for use in low light.

Category 2

Medium tint, suitable for moderate light.

Category 3

Dark tint, ideal for everyday use in the sun (beach, city, driving).

Category 4

Very dark, reserved for extreme conditions (high mountains, sea) – prohibited for driving.

What are the different types of sunglasses?

At Vision Janine, we primarily use CR39 and polycarbonate lenses, two materials that offer an excellent balance between comfort, protection, and durability. However, there are several types of sunglasses, each with its own unique characteristics.

Organic glasses (CR39)

Created in the 1940s, they have become a benchmark in eyewear. Lighter than mineral, they combine visual comfort, good durability, and optimal sun protection. Today, they are one of the most widely used materials in high-end fashion.

Polycarbonate lenses

Ultra-light and virtually unbreakable, they are ideal for sports and outdoor activities. Their main advantage is their shock resistance.

Mineral glasses

Made from natural glass, they offer unparalleled optical quality and excellent scratch resistance. Their disadvantage is their greater weight and their fragility in the event of impact.