Photochromatic lenses

Whether you wear glasses or not, you can get eyestrain at the end of a long day. Televisions, computer screens, sunlight, reading and driving can all put eyes under stress and strain causing blurred vision and watery eyes.

Photocromic lenses can help your eyes cope as they react to different light conditions encountered during the day.

What are photochromic lenses?

Photochromic lenses darken on exposure to sunlight and protect the eyes from ultraviolet radiation. Excessive exposure can cause permanent damage to the cornea and conjunctiva.

Good photochromic lenses block out 100% of the most harmful rays of the sun, 100% of the time, adapting to changes in light and darkening in seconds.

Whilst sunglasses give comfort in very bright conditions by reducing the total amount of light and glare reaching the eye, they are not always convenient in changing light conditions and care must be taken that they meet Standard BS 2724 otherwise they won’t protect the eye from the sun’s damaging ultraviolet rays. In fact, non-UV absorbing lenses can do more harm than not wearing any protection at all because, behind a dark tint, the pupil increases in size allowing the harmful rays through.

In this section

Why wear prescription photochromics?

Photochromic lenses offer great flexibility to anyone needing prescription eye wear, protecting the eyes indoors and out at all times. They are made in your normal prescription so your spectacles will correct your vision and give UV protection. Photochromic lenses meet all your various needs by combining the benefits of prescription spectacles / contact lenses and sunglasses.

Choose photochromic lenses

Photochromic lenses are available in glass and plastic. Historically, glass offered the best photochromic eye protection with a faster reaction and darker tint when activated. Recent innovations and some of the newer products available have shown that plastic’s performance has caught up and is now very versatile.

Glass photochromic lenses are often twice as heavy as plastic. They are not uniform in tint (which affects the colour of the lens when activated by sunlight) and are not shatter resistant. Plastic photochromic lenses, on the other hand, are both shatter and scratch resistant.

Ask your optometrist or dispensing optician about the latest product and tint range for you particular prescription.

Does the colour of the lens make a difference?

Traditionally, grey is the most popular colour in photochromic lenses, but tints can vary. Recent research shows that a brown tint is largely preferred in Europe and is widely available in most practices.

Who wears photochromic lenses?

Photochromics are versatile enough to suit almost every occasion. For golf or tennis players, where good vision is as important as comfort and protection, or schoolteachers supervising playground or sports activities as well as spending time in the classroom, photochromic lenses are ideal.

For enhanced performance your optician will tell you whether your photochromic lenses can be treated with hard coating, anti-glare and/or water repellent treatments. When combined, all three treatments make them ideal for sports and prevents misting when coming from outdoors to indoors.

Driving in photochromic lenses

Whilst driving, your photochromic lenses may not become as dark as they do outside. This is nothing to worry about, whether the lenses are activated or not your eyes are still being fully protected by the windscreen, which blocks out the harmful ultraviolet light that would normally make the photochromic lenses darken.

What about extreme conditions of sunlight?

People exposed to intense periods of extreme heat and high levels of UV should consider a second pair of prescription sunglasses made to the British Standard 2724. But in most day to day situations and activities, photochromic lenses are the most versatile option for prescription wearers.

Tips for handling and taking care of your frames and lenses

Follow the advice of your optometrist or dispensing optician about how to look after your photochromic lenses. Here are some basic guidelines:

Keep your lenses and frames clean.

To clean lenses, your practitioner will advise you whether you should dip them into warm, soapy water and rinse them under running water, or use a spray and special microfibre cloth suitable for plastic lenses.

Use two hands to remove your spectacles, using even pressure on both side pieces.

Keep your glasses in a case. Open the case fully and gently pull them out (sliding them in and out may dull the lenses).

REMEMBER – If you put your photochromic lenses in a glasses’ case before they have completely lightened, you may find that they are still dark when you take them out again. As soon as they are exposed to indoor light, they will lighten again.

We are indebted to the Eyecare Trust for providing the content for this section