Transitions Materials:

Transitions Optical's technology can perform on a vast array of materials, lens designs and lens configurations including availability in single-vision, bifocals, trifocals or progressives.

These dynamic lenses also come in both standard and higher refractive index lens materials from 1.50 up to 1.74. There's a Transitions lens available to fit any frame you prefer and in a material to fit your lifestyle. Want more? Transitions lenses are also available in gray or brown.

UV and Visible Light:

lPhotochromic molecules are the "magic" technology inside each Transitions lens. As you experience different lighting conditions throughout your day, the molecules adapt by changing structure. This automatic change causes the lens to get darker, as well as return to be as clear as an ordinary, non-photochromic lens.

The molecules are triggered to change by exposure to specific wave-lengths of light. Original Transitions lenses are activated by UV light. This is why the lens activates when outdoors but not indoors. Transitions XTRActive lenses are activated by UV light as well as visible wavelengths of purple and blue light giving the lens slight activation indoors and increased activation behind the windshield of the car and even more activation outdoors.

The family of Transitions lens products continues to be the most advanced featuring photochromic technology and remains the best choice to enhance your ability to discern objects of varying size, brightness and contrast, giving you the gift of better sight everyday and in any light condition.

Transitions lenses employ photochromic technology to change the way you see the world. UV light from the sun causes a chemical reaction inside our lenses to produce varying degrees of darkness. On a cloudy day, in shade, or when the sun

is setting and the amount of UV light is minimal, the molecules only slightly activate. This moderate activation is intentional to allow just the right amount of light to pass through the lens to reach your eyes so that you can see clearly and comfortably, regardless of the time of day and lighting conditions.

In the presence of UV rays, our clear, polycarbonate lenses start growing darker in only a matter of seconds, typically reaching 70% activation within 35 seconds. When UV rays are no longer present, our lenses immediately begin to fade back and become clear lenses in just a few minutes.

Regardless of the amount of light present, Transitions lenses always block harmful UVA and UVB.

Reducing Eye Fatique:

In the fight to help eliminate glare and reduce eye strain, Transitions lenses are always working for you.

Low lighting conditions cause the eye to work overtime when seeing or reading and can contribute to sore, tired eyes or even headaches.

Bright lighting conditions elicit a universal reaction from the human eye; squinting. Squinting causes the pupil to constrict and is a natural attempt to block the amount of light entering the eye. This constriction of the pupil is one reason why eyes may feel strain or pain in bright light conditions.

Because photochromic lenses react to the amount of UV light exposure, Transitions lenses provide comfort and convenience by automatically adjusting to control the amount of light that reaches the eye.

Behind the Windshield:

Because the glass in car windshields blocks most UV rays, less than 1% of the available outdoor UV energy reaches the lenses of the driver. Traditional photochromic lenses just do not receive sufficient energy to provide significant darkening while driving.

For these situations, we offer an everyday lens solution, Transition® XTRActive™ lenses or, suggest drivers consider a second pair of sunglasses or a specialized product such as polarized Drivewear ® Transitions® SOLFX™ lenses. These lenses contain a specially designed photochromic dye that responds to both UV and natural (visible, clear, or white) light and can activate behind a windshield.

Temperature:

Photochromism—the science behind the lenses automatically adapting—is guided by the laws of Physical Science. All photochromic molecules are activated by light energy (sunlight) and deactivated by heat energy (heat). Sunlight makes the lenses dark and heat makes the lenses clear.

When exposed to certain wave lengths of light, a bond within the photochromic molecules is broken and the molecules instantaneously open—darkening the lens. When exposed to heat, the open bond within the photochromic molecules close, returning to a clear lens. For example, when you are outdoors on a warm sunny day, the photochromic molecules are opening because of the exposure to sunlight and, at the same time, closing because of the warm temperature (heat energy). This activity of opening and closing is rapidly ongoing and what allows the lens to adapt when moving through varying light conditions.

The darkness of the lens is dependent on the number of photochromic molecules open at any given time. In hotter temperatures-- think of a pot of boiling water—the molecules have more energy and are closing at a faster rate. Therefore, although the amount of light energy (sunlight) present is the same, the number of open molecules on a hot day is less than the number of open molecules on a very cold day. This is why a photochromic lens is darkest in cold temperatures and returns to clear quicker in warmer temperatures.

Transitions lenses are the number one recommended photochromic lens worldwide. Our scientists are always challenging themselves to improve our photochromic technology and create products with improved temperature independency. In fact, the latest Transitions lenses become 10 percent darker in hot temperatures than the previous generation.

The Transitions Lens Process:

Through a series of specialized processes called imbibing and trans-bonding, the photochromic dye becomes a part of the lens—similar to staining a piece of wood (imbibing) or applying fingernail polish (Trans-Bonding™).

Trans-Bonding takes place when scientists apply proprietary surface treatments in a series of layers. Trans-Bonding provides outstanding adhesion, scratch resistance, optical purity, and photochromic performance.

Through a series of specialized processes called imbibing and trans-bonding, the photochromic dye becomes a part of the lens—similar to staining a piece of wood (imbibing) or applying fingernail polish (Trans-Bonding™).

Trans-Bonding takes place when scientists apply proprietary surface treatments in a series of layers. Trans-Bonding provides outstanding adhesion, scratch resistance, optical purity, and photochromic performance.