Why Don’t Transition Lenses Work Well in the Car?

The value and convenience of Transition lenses are well known to consumers, but there is one area where they suffer from seemingly uneven performance: they do not fully darken when worn inside an automobile, regardless of the brightness of the day and the amount of light to which they’re exposed. Are the lenses to blame for this anomaly in performance? The answer lies in the way Transition lenses work—they darken in response to ultraviolet (UV) light. However, most modern automobile windshields block UV rays to protect passengers, preventing the lenses from fully activating.

Fortunately, solutions such as the DriveWear from Transitions Optical, which darken using visible light, offer improved performance for drivers, ensuring comfort and convenience even behind the windshield. In this article, we’ll explore why standard Transition lenses don’t fully darken inside cars, delve into the science behind this phenomenon, and discuss available solutions that offer improved performance behind the windshield.

Transition (or photochromic) lenses actually work the same way in the car as they do anywhere else – they variably darken in reaction to the presence of ultraviolent (UV) light. The problem stems from the fact that most modern automobile windshields already filter out harmful UV rays.

“Your windshield is normally quite different from the rest of your glass, in that it’s two pieces of glass laminated with a layer of plastic – vinyl – in between,” Rob Vandal, Vice-President of Product Engineering and Development at Guardian Automotive (a supplier of original equipment windshields to major automakers), explained in a recent interview. “So that triple-layer system…contains UV inhibitors that protect the plastic and as a result also protect any transmission of UV through it. So a windshield, laminated glass, blocks 98 to 99 percent of all UV.”

Ultraviolet light operates below the visible spectrum and is invisible to the human eye. Its presence and effect has nothing to do with the brightness of sunlight; that is why you can still get a sunburn if you lay out on cloudy day. This sometimes leads to confusion over the effectiveness of Transition lenses, and questions like, “If bright sunlight is entering my car (and my eyes!), why aren’t my photochromic lenses darkening to compensate? Are they defective?”

No, your Transition lenses are working just fine. They simply can’t react to a light source that is not present, and in an automobile, most of that UV light has already been taken out of the equation. You may notice some darkening of your lenses while in your car; this is because in typical automotive applications, only the windshield blocks a high percentage of UV light. Side and rear glass is rarely laminated, so while it has some UV-blocking properties, it also lets a good deal of ultraviolet light spill through.  And, of course, open windows allow in some ambient UV light, sometimes enough for your Transitions to react.

Transitions Lenses in the Car

So how to combat this effect? If your prescription photochromic lenses do not sufficiently darken to your comfort level while in the car, you have options. You can purchase a separate pair of prescription sunglasses for driving. You can buy clip-on sunglasses to apply temporarily over your prescription eyeglasses. And Transitions Optical has recently developed and marketed a series of eyewear which does darken behind the windshield of a car.

Unlike other transitions, the Transitions DriveWear work well behind a car’s windshield. This is because it operates using visible light, which can easily penetrate the windshield. In contrast, other transition lenses depend on UV light to activate their darkening effect. Since a car’s windshield is designed to block a significant amount of UV light to protect passengers, these other transitions do not function effectively in such an environment. Therefore, it provides a distinct advantage for those who need their lenses to adapt to changing light conditions while driving.

How to Order glasses with Transitions lenses

1. SELECT THE FRAME

RX Safety offers a wide range of safety glasses, eyeglasses, and sunglasses that are prescription available. Choose your favorite one.

AFTER CHOOSING THE PERFECT FRAME, CLICK IN ‘SELECT PRESCRIPTION LENSES’

3. SELECT LENS COLOR

Customize your lenses by choosing your lens color. This is where you select your favorite Transition option, including Drivewear.

SELECT YOUR FAVORITE LENS COLOR

5. ADD YOUR PRESCRIPTION INFORMATION

Now it is the time to upload or fill your prescription information. You’re done! The rest is with us. We will work on your Transition glasses and deliver to your address.

ADD YOUR PRESCRIPTION INFORMATION