Among all sunwear products, photochromic sunglasses are widely considered as an advanced form. It is widely known that regular sunglasses are made with fixed degrees of darkness in the lenses. In this case, dark lenses usually block more sunlight, while light ones have a weaker ability in sunlight filtration. However, sunglasses using photochromic lenses are completely different that they are adjustable in different lighting conditions. A basic point of these lenses is that they darken on exposure to ultraviolet radiation and gradually return to a clear state when the UV is removed when the wearer enters indoors. Some people may think that this is a magic capability. And what is more exciting, this ability does not rely on a special lens material. It is feasible to use glass, polycarbonate or other plastics to produce photochromic lenses. In recent years, these products have been quite popular.

The photochromic properties of these lenses are created by embedding microcrystalline silver halides or molecules in a glass substrate. While using plastic materials, manufacturers apply organic photochromic molecules to achieve the reversible darkening effect. And the UV rays contained in sunlight are the exact part that causes the lenses to darken. This basic fact explains why these lenses will not become dark with exposure to room light. Photochromic sunglasses have been widely praised due to this advanced functionality. In most cases, they use prescription lenses so that such a pair will function as regular Rx glasses when staying indoors. This greatly eliminates the need to change separate pairs of glasses and sunglasses when it is necessary to make switches between indoor and outdoor environments.

A disappointing fact may be that these sunglasses are imperfect. Photochromic sun glasses made by different corporations usually take a little bit longer to clear than to darken. In an extreme case, it may take up to an hour for these lenses to clear. During this transition time, normal, clear vision will be affected. Another drawback of photochromic sunglasses is that they also react to temperature that they darken much more in cold conditions. This indicates that these sunglasses will work less effectively in summer. It is necessary for customers who are interested to know these points.

Related pages – UV sunglasses, Polarized Bifocal Sunglasses, Progressive Sunglasses

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