Having in mind the traveler's needs, National Geographic has created a tool to protect eyes from the harmful effects of the direct sun rays. National Geographic Sun Gear is equipped with specific, high tech sun-lenses designed to perform in different lighting conditions, latitude, outdoors activities. Each frame is made with great attention, combining innovative technical solutions with the quality and taste of traditional handmade production.

The lens does not have any colours added through external coating, nor mirror coatings, therefore its typical colour is due to the combination of the two glass wafers (slightly coloured) and the polarized film.

• UV and IR sun filters. Sun filters protect eyes by decreasing the amount of light energy, both assuring that a certain amount of light passes the lenses. This quantity is established by norms, which regulate the production of sun filters (see chart). UV filters protect against ultraviolet rays, which are not visible to the human eye but can be very dangerous, especially during prolonged exposure. IR filters protect against infra-red rays and improve comfort reducing the heating effect, especially at high altitudes.

• Polarized lenses. Polarized light is everywhere around us causing reflected light and glare under the sun. Polarized lenses are useful in all cases in which shiny surfaces such as water, snow, glaciers, asphalt or sand dominate the scene.

• Oleophobic coating. This coating makes water drops roll off the lens surface without sticking, so sunglasses can perform at maximum level for all outdoor activities, under splashy wet conditions, rain or snow. What’s more, it prevents dust, fingerprints and impurities from adhering to the lens.

• Anti-reflexion treatment. The inside of the lens has an anti-reflexion treatment that eliminates the reflexion of incident light on the surface.

• Color features. Lenses can be of almost any color, but a certain color is more adapt for a certain situation. Grey lenses are usually thought to be more neutral in color interpretation. Brown is known to be more comfortable because of its warm shades. Green lenses enhance nature’s colors, especially floral ones. However protection from UV rays never depends on how dark the lens is.

• Lenses - Glass - Optical. Glass lenses are made by Barberini, a world leader in optical glass manufacturing. To Barberini only the natural purity of glass can assure the best optical precision and the inalterability of its characteristics along with its typical and unique transparency. Glass is resistant to heat and chemical agents, will not change shape and produces good optical surfaces. Optical glass produces low color dispersion, and therefore, good optical imaging with no color fringe. Neophan glass sun lenses represent the state-of-art in eye protection against harmful sun rays. Each polarized lens consists of several elements, laminated together. The entire process is completely automated to guarantee consistent high quality in the final product.

• Active Lenses. These lenses are made with F.R.P©. a flexible, robust yet lightweight polymer which has excellent impact resistance, total UV protection and good anti scratch properties.

• Light Lenses. These lenses are made with CR-39, a lightweight plastic polymer with a good index of refraction. It is resistant to most solvents and chemicals, to aging and to material fatigue.