How do Transition Lenses Work? The Science Behind Highly Functional Eyewear

Transition lenses or light-adaptive lenses are lenses that darken when exposed to UV rays. It is a high-quality photochromic lens that helps to block out or protect the eyes from UVA and UVB rays from the sun. These lenses have an adaptive technology that accommodates every prescription, style, and frame. Read on to learn how transition lenses work.

Transition Lenses

These lenses can go as dark as regular sunglasses. However, the level of darkness depends on the surrounding environment. It also depends on the level of UV exposure and temperature. Transition lenses are eyeglass lenses that have vision correction and sun protection features. There are various colors and style options; however, some are exclusive to certain transition styles. 

How Transition Lenses Work

When most individuals see the lenses change from eyeglasses to sunglasses, they wonder, “How do transition lenses work?”. First, it is vital to note that transition lenses are a named or branded type of photochromic lens. The photochromic molecules in the lens are sensitive to the amount and presence of UV light. 

Photochromic lenses are light adaptive lenses with photochromic molecules in dyes in the lenses. These molecules in the lens dye change their structure when exposed to UV light. The amount of UV light that passes through the lenses causes the molecules to change their structure proportionally. It causes the lens to darken to a comfortable shade allowing vision.

When in direct sunlight, the transition lenses will darken to their darkest shade. Although an overcast sky or weather will still adjust the transition lenses, it will not be as dark as when in direct sunlight. Also, the photochromic molecules will become clear and light when transitioning from a place with UV light to one without UV light rays. 

Benefits of Transition Lenses

Transition lenses are convenient lenses that offer the individual a range of benefits. Some of these benefits are:

A Continuous UV Protection

One widely known benefit of transition lenses is the continuous UVA and UVB sun rays protection. These rays are harmful and can damage the eye’s macula, which controls the central vision.

Wearing a sun-protective transition eyeglass lens outside will protect your macula cells. Transition lenses also protect the eyes from blue light from various digital screens.  


Another benefit of transition eyeglass lenses is their versatility. The versatility of these lenses enables an individual to have one pair of glasses as prescription glasses and sunglasses. The transition lenses will allow you to use a pair indoors or outdoors.

Cost Effective 

Although transition eyeglass lenses are not cheap, the investment is cost-effective in the long run. The individual will spend less purchasing transition eyeglasses, which can be a prescription and sunglasses. It is a better choice compared to having to buy a separate pair of sunglasses and a prescription. 

Transition glasses give a two-in-one experience, serving as a middle ground between sunglasses and eyeglasses. 

Prevent Eye Strain

Transition eyeglasses help to block UV rays that cut bright glare when we step outside. It helps to prevent eye straining that may occur from constant squinting because of the bright light. You can keep your eyes comfortable with transition eyeglass lenses instead of trying to see through the bright sunlight. 

Easy Customization 

One major thing to consider when choosing an eyeglass is the lens color. Most individuals often wonder if the selected lens color will suit what they do. Although transition lenses are imperfect, they allow individuals to adjust better to their lifestyles. It helps to reduce the costs of spending on various pairs of glasses that may break or be lost. 

Drawbacks of Transition Lenses

Although transition lenses have a range of benefits, they also have some drawbacks. Some of these drawbacks are:

Slow Transitions in Cold Weather

There are transition lenses that often take longer to darken or adjust in cold weather situations. The molecules in the lenses move slower during cold weather, causing a slow transition. Prolonged exposure to cold air can reduce the reaction time of the lenses significantly.

Not as Effective in Vehicles

The reaction of transition lenses to UV rays is what causes them to darken. However, since most windshields block considerable UV rays, transition lenses are often ineffective in vehicles. Some types of transition lenses receive little to no UV rays in the vehicle, preventing them from darkening. 

Lack of Polarization

One of the reasons why individuals wear sunglasses is the polarization of several shades. Polarized lenses have a reflective coating. The reflective coating helps to shield the eyes from the UV rays. Polarized lenses also help when looking at reflective surfaces like snow or water. However, transition lenses do not possess polarization. Although these lenses can help shade the eyes from light, not all can reflect harsh glares. 

Transition Lenses Are a Functional Eyewear

Transition lenses protect the eyes from blue light and UV rays. These lenses are transparent indoors and darken when exposed to UV rays to give a sunglass effect. The lenses can serve as an adornment, protect the eyes from UV rays and also improve vision based on the prescription. This benefit is one of the reasons why transition lenses are a popular choice worldwide.