Photochromic lenses: What are Transition Lenses?

Medically reviewed by Wut Win, Dispensing Optician at Feel Good Contacts.

Photochromic lenses are an advanced lens technology that causes lenses to turn darker when you’re outdoors/exposed to UV light and to turn back to clear when you are indoors. Today, you can choose from a wide range of photochromic lenses for glasses and sunglasses in a variety of different colours. The options can be overwhelming, so in this post we break down what photochromic lenses are and whether they are a good option for your lifestyle.

What are photochromic lenses for glasses?

Photochromic lenses, also known as light-adaptive lenses, are eyeglass lenses that automatically darken when exposed to sunlight and ultraviolet rays. This function protects the eyes from damaging ultraviolet radiation.

Are photochromic lenses good for your eyes?

Photochromic lenses are good for your eyes and offer many benefits. However, whilst glasses with photochromic lenses certainly offer convenience, they may not be the right lenses for you. Here are some pros and cons so that you can weigh up the advantages and disadvantages of photochromic lenses before you make a commitment.

Photochromic lenses advantages


In general, you don’t need to carry sunglasses with you if you have the photochromic technology built into your prescription glasses. However, people exposed to intense periods of extreme heat and high levels of UV should consider a second pair of prescription sunglasses.

Comfort and protection

  • Less glare means reduced eye strain and eye fatigue
  • Reduced exposure prevents dry eye
  • They offer 100% UV protection and block UVA/UVB light
  • Protecting your eyes in this digital era is important and these lenses even block blue light which is known for contributing towards digital eye strain and eye fatigue
  • Ideal for those with eyes that are very sensitive to light


You save money by purchasing the one pair of glasses, without having to buy prescription glasses and sunglasses separately.

Carrying around two pairs of glasses also means that you’re much more likely to lose or misplace one of them so having just one pair is better.


They are featured in a range of colours and styles whilst still being able meet your prescription needs. You can choose any frame you like and have them fitted with transition lenses.

Photochromic lenses disadvantages

Dependent on light conditions, some lenses take longer to adjust and change in the light than others. Different brands have different levels of darkness and different reaction times for their photochromic lenses. This can impact performance in vigorous activities such as sports, so you’ll need to consider this for sports sunglasses.

Importantly, lenses are also unlikely to change colour inside of your car. This is because the majority of car windshields filter out all the UVB rays and approximately a third of the UVA rays that activate transition. Nevertheless, recent advancements in technology allow some photochromic lenses to be activated by visible light, resulting in a certain level of darkening behind the windshield.

uv rays

How do photochromic lenses work?

Photochromic lenses are clear or light when the wearer is inside and turn dark when they are outside. At the peak of transition, lenses can become as dark as sunglasses in bright, natural sunlight and as clear as normal prescription glasses when they are not activated. The lenses can be made from glass or plastic and come in a range of colours.

The lenses in photochromic glasses feature extraordinary technology that causes the lenses to change in colour when they are activated by UV rays (ultraviolet radiation).

The UV rays from the sun affect molecules in the lenses, prompting them to change colour and automatically darken as they absorb the sunlight. You can even expect the lenses to darken in cold weather and on cloudy days as UV light still penetrates through cloud.

They adapt through to different darker shades, depending on the levels of UV light. The darkening process can take a few minutes before the tint takes effect on the glasses once you’re outdoors, and it can take a similar time to return to clear when going back indoors.

Photochromic glasses offer great flexibility to anyone needing prescription eyewear, protecting the eyes indoors and outdoors at all times. They can be made according to your normal prescription so that the spectacles will correct your vision and give UV protection at the same time.

Photochromic lenses and blue light

In addition to protecting your eyes from UV rays and outdoor glare, photochromic lenses also provide protection from blue light. Exposure to blue light from digital devices such as smartphones and computer screens can lead to digital eye strain, possibly headaches or noticeable eye fatigue.

What is the difference between photochromic and polarised lenses?

Photochromic and polarised lenses are not the same. Photochromic lenses are light intelligent lenses which transition and adapt to daylight, whereas polarised lenses have a polarising filter applied to the lens which blocks horizontal light and eliminates reflective glare. Polarised lenses, unlike photochromic lenses, are permanently tinted without changing in colour.

Whilst, photochromic lenses can be ideal for everyday use, polarised lenses are great for daytime and outdoor use only. They are a great option for driving because they reduce reflective glare from the road and the car hood, providing optimum visual comfort and contrast.

What is the difference between photochromic lenses and transition lenses?

Photochromic lenses are also known as transition lenses. Both refer to glasses lenses that change in colour when exposed to bright sunlight.

Transitions is a leading photochromic lens brands, popular due to its advanced technology in lens development. For many it has become a household name that is synonymous with photochromic lenses. That is why photochromic lenses are commonly referred to as transition lenses, but there are many other manufacturers.

Photochromic brands

There is now a wide selection of photochromic brands to choose from in Ireland and globally, our favourite being Transitions.

Transitions has developed a range of light-adaptive lenses with different properties for different use-cases. Top Transitions lenses products include:

Transitions Signature GEN 8
Using two pioneering processes called imbibing and Trans-Bonding, Transitions Signature GEN 8 represents the latest advancement in Transitions adaptive lenses. They are the quickest of all transition products to fade back to clear indoors and are available in the widest variety of shades. Choose from Grey, Brown and Graphite Green, also now in Sapphire, Amethyst and Amber.
Transitions XTRActive (New Generation)
Designed for those who have light sensitivity indoors and require a darker lens when driving as well as when being outside. The slight tint indoors ensures optimal comfort when exposed to harsh lighting. They also darken behind the windscreen of a car as they respond to both UV light and natural (visible, clear or white) light.
Transitions Drivewear
Glasses specifically developed with driving conditions in mind. The lenses darken outdoors and transition to a faded tint indoors, or behind the steering wheel. They provide sharper vision and enhanced colour perception, transitioning from yellow/green in low light, copper in moderate to bright light, and a dark reddish brown in bright light. They give 100% protection from UVA and UVB rays.

Alternatives include:

Light Reactive (Feel Good Contacts)
These lenses use photochromic technology to remain clear indoors and seamlessly darken outdoors, blocking 100% of UVA/B light. Available in Grey and Brown, these are an affordable and effective option for transforming your desired frame into light-adaptive apparatus.
Sensity (Hoya Vision Care)
Sensity photochromic lenses feature trademarked technology to ensure the lenses adapt to a range of climates and temperatures. These lenses by Hoya are available in Silver Grey, Emerald Green, and Bronze Brown colours. They are featured in a variety of lens designs, materials and anti-reflective coatings.
PhotoFusion (Carl Zeiss Vision)
PhotoFusion X lenses come in many different colours and are designed to offer accurate colour vision under all lighting conditions. These lenses darken and lighten indoors up to twice as fast as other Zeiss photochromic lenses.
ColorMatic (Rodenstock)
ColorMatic lenses by Rodenstock are available in wide selection of colours. ColourMatic 3 offers 30% faster brightening compared to the previous generation ColorMatic IQ 2.
PhotoView (Signet Armorlite)
Made of lightweight plastic and polycarbonate, PhotoView photochromic lenses are available in a range of lens designs such as Kodak progressive lenses.

How to buy transition lenses

  • 01Choose the glasses frames you wish to purchase and select 'choose your lenses'Choose the glasses frames
  • 02Decide on what you will use your glasses for.Decide on what you will use your glasses
  • 03Enter your prescription or select 'send later'.Enter your prescription
  • 04Select 'Transitions' and don't forget to pick a colour.Select Transitions
  • 05Choose a package and coating to suit you.Choose a package and coating

What is the best colour for transition lenses?

The best colour for transition lenses depends on the colour of the frames you have selected. If you choose black frames for example, we recommend opting for green or grey transition lenses. Brown lenses look best with golden frames.

best colour for transition lenses
best colour for transition lenses
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best colour for transition lenses
best colour for transition lenses
best colour for transition lenses

How to test photochromic lenses

You can test your photochromic glasses by simply putting them on and going outside, especially on a bright, sunny day. You will notice them immediately darken. Once you go back inside, you’ll notice them lighten to clear or to a lighter shade after a few minutes.

If you need any help with buying glasses with photochromic lens technology online or you’re not sure what type of lens you need, don’t hesitate to contact us by email at, on WhatsApp or by phoning us on 01 514 3614.

Disclaimer: The advice in this article is for informational purposes only and does not replace medical care or an in-person check-up. Please check with an eyecare professional before purchasing any products or remedies. For information on our article review process, please refer to our Editorial Policy.

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