What is photochromic lens?
Photochromic lenses automatically adjust their tint based on UV levels.
In bright outdoor conditions, the lenses darken to protect your eyes like sunglasses. In low UV environments—such as indoors, on cloudy days, in the shade, or at night—they become lighter for a clearer view.
Regardless of tint level, they block over 99.9% of UV rays.
SWANS’ photochromic technology adjusts quickly to changing light and responds even to low levels of UV.
FEATURES
Gradual Light Adjustment
The lens tint changes gradually rather than instantly. The speed of adjustment varies depending on UV levels and temperature, naturally adapting to your surroundings.
*Please note that the lenses do not instantly change brightness in sudden transitions, such as entering a tunnel.
Affected by Temperature
Lens tint is affected not only by UV levels but also by temperature. While stronger sunlight generally darkens the lenses, higher temperatures can reduce this effect. Conversely, lenses tend to darken more in colder conditions.
As a result, on hot days, the lenses may appear less dark than expected.
*If a darker tint is needed, we recommend using a separate pair of sunglasses depending on the conditions.
Gradual Reduction in Photochromic Performance
The photochromic function may gradually decrease with use, becoming less responsive to changes in light, while UV protection remains unaffected.
Frequent use and UV exposure may speed up this process. Store the lenses in a case when not in use.
Best Situations for Photochromic Lenses
Road Cycling / Running
Photochromic lenses are ideal for commuting rides in the early morning or evening, where light conditions change. While the shift in tint may feel subtle, the lenses are continuously adjusting to maintain a comfortable level of brightness.
Hiking / Trekking
Ideal for environments where light conditions change frequently, such as in the mountains. You can start wearing them before sunrise, eliminating the need to switch to sunglasses during your activity.
Important notes
・Lens Tint Varies with UV Exposure
Lens darkness depends on the amount of UV exposure. When UV is blocked—such as by a hat or umbrella—the lenses may not darken as much, even in bright conditions.
・No Darkening Indoors or in Vehicles
The lenses do not darken inside cars or indoors, as UV-blocking glass prevents UV from reaching the lenses.
・Gradual Tint Adjustment
The lenses take time to return from dark to clear. In colder conditions, they may darken more and take longer to fade compared to warmer environments.
FAQs
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Do photochromic lenses have a lifespan?
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The dimming function gradually decreases and becomes difficult to change.Please check the dimming function before use.If the change is difficult to notice, please replace it.
･Store sunglasses in a dark place. (about 1 hour if possible)
･Then, leave it outside on a sunny day for about 5 minutes and check the tint status of the lens.
(It will be easier to see the change if you cover part of the lens with aluminum foil, etc., and compare the areas that are exposed to light and the areas that are not.)
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Please tell me how to store photochromic lenses.
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When storing, avoid high temperature and humidity, and store in a dark place such as in a case.
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Can I use a lens with reduced light control function?
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Even after the dimming function decreases, the UV cut function is maintained, so you can prevent the effects of UV rays.
However, dimming cannot reduce glare, so if you find it too bright, we recommend replacing it.
It is possible that deterioration over time has affected things other than the dimming function, so if you continue to use it, please replace it if there is any abnormality in the lens or frame.
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I find it difficult to change the color of the photochromic lenses during the summer.
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Photochromic lenses are colored by the amount of ultraviolet rays, but they tend to become brighter as the temperature rises.
Therefore, the color of the lenses will change depending on the amount of UV rays and the temperature where they are used.
From the above, even if the amount of UV rays is the same, the color of the lenses tends to become darker in the winter when the temperature is lower, and it tends to be lighter in the summer when the temperature is higher.
