If light conditions remained as constant as they are in the eyecare professional’s exam room, you wouldn’t need anything more than clear lenses in your glasses.  Transitions lenses are clear indoors and at night but automatically adjust their level of tint to changing light conditions outdoors.  Transitions lenses change from clear to dark in the presence of ultraviolet (UV) radiation, such as when exposed to sunlight. Indoors and at night, Transitions lenses are as clear as regular clear lenses. Outdoors, when exposed to the sun’s UV rays, they turn sunglass dark. 
But Transitions lenses don’t stop at improving visual quality and visual comfort. Like skin, our eyes need sun protection too. Transitions lenses provide UV400 protection, blocking 100% of damaging UVA and UVB radiation and helping to preserve your long-term eye health. Transitions lenses are the #1 recommended photochromic lenses by eyecare professionals worldwide.
Transitions lenses are the first lenses to earn the American Optometric Association (AOA) Seal of Acceptance for UV Absorbers/Blockers and the first to receive the World Council of Optometry (WCO) Global Seal of Acceptance for Ultraviolet Absorbers and Blockers based on the WCO's scientific testing protocol. Additionally, Transitions lenses meet internationally recognized standards for UV blockage, including ANSI Z80.3, ISO 8980-3, EN 1836 and AS/NZS 1067.

Transitions - Photochromic Lens Technology
Transitions Overview
Transitions lenses
Younger Optics is proud to offer Transitions® lenses, the ideal choice for your everyday lenses. Transitions lenses contain patented photochromic dyes which cause the lens to activate - or darken - when exposed to ultraviolet (UV) rays from sunlight. When the UV light diminishes, the lenses fade back to clear. As outdoor light conditions change, the level of darkness adjusts, creating just the right level of tint and allowing just the right amount of light to enter the eyes at any given time. This action allows Transitions lenses to help protect your eyes from visible light, reducing glare, diminishing eye strain and fatigue and enabling you to distinguish contrast more easily.
Transitions Technology
Superior photochromic lenses must be anchored by a solid, high performance foundation—that foundation is the lens material matrix. Transitions Optical works hand in hand with Younger Optics to design expertly formulated lens material foundations, which are fully optimized for photochromic speed, darkness, indoor clarity and photochromic lifetime.  The lens material matrix provides a concrete but versatile platform that assures that Transitions lenses are available for virtually any frame—including popular 3-piece rimless frames—and in nearly every design and material imaginable—including the IMAGE® progressive design and thinner, lighter, shatter-resistant Trilogy® lenses.
Younger Optics is proud to offer a full array of Transitions products.  We offer Transitions on our award winning Image progressive and single vision in hard resin, polycarbonate, 1.60, 1.67 MR-10 & Trilogy.  We also offer a full range of bifocals and trifocals with Transitions in hard resin as well as the newly released Trilogy FT bifocal, the only bifocal available with Transitions and superior impact resistance.
Transitions Support
Transitions Optical leads the industry in developing and marketing photochromic lenses. Transitions works to raise global awareness of the dangers of UV rays to the eyes and how glare can compromise the quality of everyday vision. Younger Optics and Transitions provides quality products that help people protect themselves against these dangers, and maintain the health of their eyes. We partner with optical labs and ECPs, providing clinical and educational support. We also offer strong marketing support to help their businesses grow.