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Photochromic lenses: What are Transition Lenses?
Medically reviewed by Alastair Lockwood on 28 September 2021
Photochromic lenses are an advanced lens technology, that causes your lenses to turn darker when you’re outdoors/exposed to UV light and turn lighter when you are indoors. Today, you can choose from a wide range of photochromic lenses in glasses and sunglasses with different shapes and colours. 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 protect the eyes from ultraviolet radiation. The lenses are clear or light inside and turn dark outside. Photochromic lenses can darken to anywhere between 60-80% in bright, natural sunlight. The lenses can be made from glass, polycarbonate or plastic.
Photochromic glasses offer great flexibility to anyone needing prescription eye wear, protecting the eyes indoors and outdoors at all times. They are made in your normal prescription so your spectacles will correct your vision and give UV protection.
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 and possibly even macular degeneration in the long run.
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 lighting, whereas polarised lenses feature a chemical applied to the lenses in a vertical pattern. This blocks horizontal light to eliminate glare as the horizontal wavelengths don’t fit through the vertical pattern. 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 driving. This is because they reduce horizontal glare, providing optimum visual comfort and contrast.
How do photochromic lenses work?
Photochromic lenses change in colour when 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.
They adapt through to different darker shades, depending on the levels of UV light. The darkening can take up to 30 seconds for the tint to take effect on the glasses once you’re outdoors, and it can take between two to five minutes to return to normal when going back indoors.
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.
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
- 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 sleep loss
- Ideal for those with sensitive eyes
You save money by purchasing the one pair of glasses, without having to buy a pair of 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 fit with transition lenses.
Photochromic lenses disadvantages
Depending 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 with their photochromic lenses. This can get in the way of vigorous sports activities, so you’ll need to consider this for sports sunglasses. The lenses also won’t change colour inside of your car as your windscreen has UV blockage.
Nevertheless, recent advancements in technology allow some photochromic lenses to be activated by visible light, resulting in a certain level of darkening behind the windscreen.
What is the difference between photochromic lenses and transition lenses?
Photochromic lenses are also known as transition lenses. They change in colour when exposed to bright sunlight.
Transitions also known as Transitions Signature is the most popular photochromic brand due to their advanced technology and lens development.
There are many popular photochromic brands which are sold in the UK, our favourite being Transitions Signature. These lenses feature Chromea7 technology making them 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 grey, brown and graphite green. Other brands of photochromic lenses sold in the UK include:
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.
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 a lighter shade after a few minutes.
If you need any help with buying glasses online with photochromic lens technology or you’re not sure what type of lens you need, don't hesitate to contact us by email at firstname.lastname@example.org or by phoning us on 0800 458 2090.