subject: Advanced Transition Lenses [print this page] UV rays in the sunlight are harmful to the eyes, so that sunglasses are widely used to block these rays. The primary principle of sunglasses is that they have dark lenses which filter the bright light. In recent years, photochromic lenses have been gaining popularity because they have an additional function, compared with traditional sunglass lenses. Exactly speaking, photochromic lenses can also protect the eyes from changing effect of the sunlight. These lenses can adjust themselves by producing a tint effect according to the amount of UV rays falling on them. It is understandable that there are more UV rays on a bright sunny day and less UV rays on a dull day. Photochromic lenses will generate different degrees of tint effects according to the changing sunlight.
Photochromic lenses are superior to regular lenses due to their auto adjustment. But they will function in a same way as those ordinary lenses when the wearer stays inside or when it is night. In general, these lenses can block 100% of suns harmful UVA and UVB light rays. In bright sunlight, photochromic lenses are capable enough of blocking glare and thus reducing eyestrain and fatigue. In particular, people who have ever experienced eye strain and fatigue or found themselves squinting in outdoor light will benefit more from wearing photochromic lenses.
There are now many brands of photochromic lenses, including Transitions, Reactolite, Reactions and Graduations. Among these names, Transitions produces the most advanced photochromic lenses. Transition lenses come with designs such as Standard Plastic, Poly Carbonate and so on. They are generally comfortable, fashionable and convenient. But in fact, the most important factor of photochromic lenses is the reaction time. Incorporating advanced technologies, Transition lenses react very fast to UV rays of the sun. In a normal case, they take less than 30 seconds to finish the adjustment process. Both the elderly and children are target users of Transition lenses. For childrens sake, Transitions even use sturdy, lightweight, shatter-resistant and impact resistant materials.
