How Transition Lenses Work

What Are Transition Lenses?

Transition lenses give eyeglasses the ability to change their tint level and adjust to the light that is available. They were designed to protect the eyes from harmful UV radiation and can be considered sunblock for the eyes. UVA and UVB rays are blocked 100% with the tint. Transition lenses are a proprietary product and are produced as a whole lens and are appropriate as an addition to most frames. The lenses can be used in single vision, bifocals, progressive and trifocals.

What Makes Them Work?

The lenses are called photochromic, which means they respond to ultra-violet radiation. The tint is a patented dye that activates the lens. Variation in light conditions, temperature and lens material interact with the tint or coating embedded in the lens and cause the lens to darken and lighten. The stronger and brighter the UV light, the darker the lens will be. The process can cause the lens to fade into various stages of light and dark, depending on the amount of UV rays they are interacting with. The process is automatic and wearers of transition lenses say they hardly notice the changes as they occur.

Why Use Transition Lenses?

When moving from light source to light source the eyes must adapt, refocus and adjust. This can cause temporary responses in the eye that can momentarily obscure objects or focus before the eye adjusts. The quality of vision is better when the eye can adjust easily. Transition lenses reduce glare and thereby eye strain, minimize eye fatigue and enhance contrast. This aids the long-term health of the eyes. Transitions lenses are especially useful to the eye health of children. Due to the nature of the development of the eye, children's eyes are susceptible to cumulative UV radiation effects more than adults.

UV Protection

Ultra-violet rays come from the invisible portion of the light spectrum. UVA and UVB are the most harmful of the ultra-violet rays. UV radiation is proven to be the cause of a variety of eye problems --- cataracts, macular degeneration, pterygium (growth on the eye), sunburn of the eyelids and skin cancers on the skin around the eye are some examples. Protecting the eye is important in the prevention of eye disease.