Slip, Slop, Slap, AND Wrap - UV and Our Eyes:
WHAT IS UV LIGHT?
As you can see from the image above, the sun emits all sorts of radiation, namely:
· infra-red radiation – we feel as heat
· visible light – sunlight we can see
· ultraviolet radiation (UV) – we can’t see or feel
On that electromagnetic spectrum, UV falls just before visible light - it has a shorter wavelength than visible light and is thus invisible to the human eye. This shorter wavelength also means it has a higher frequency and energy than visible light, making it more dangerous.
UV is classified into 3 types, according to wavelength:
· UVC – the shortest wavelength – most dangerous, but absorbed by the Earth’s atmosphere
· UVB – associated with sunburn, skin damage, and skin cancer
· UVA – the longest wavelength – associated with skin ageing (wrinkles, sagging) and skin cancer
Unprotected exposure to UVA and UVB radiation cause damage to our DNA, and the effect is cumulative, increasing your skin cancer risk over time. Dermatologists say there is no ‘safe level’ of UV exposure, and in 2011 the World Health Organisation (WHO) classified all categories of UV as a group 1 carcinogen.
HOW DOES THIS RELATE TO MY EYES?
We’re all pretty aware of the harmful effects of UV exposure to our skin, particularly in New Zealand and Australia, but were you aware that our eyes are just as susceptible to damage? It’s a common misconception that if you don’t get light sensitive, or worry about glare when outdoors that your eyes will be fine. However, regardless of perceived sensitivity, no one is immune to the effect of UV and exposure has been linked to ocular problems such as cataract, pterygia (growth on the white of the eye), reactivation of herpetic infection, macula degeneration (AMD), and skin cancers. In fact, 90% of all skin cancers occur above the neck, and 5-10% of all cancers occur on or around the eyes.
Some of these skin cancers can be small and impossible to see well with the naked eye. At Eyes of Howick your optometrist will use a device called a slitlamp microscope when conducting your comprehensive eye examination, in order to gain a magnified view of your eyes and eyelids. This can help identify any spots or lumps of concern, allow us to take detailed images, and track for any changes.
If you have any lid lumps or lesions you are concerned about, contact us today to book in for a consultation.
WHEN ARE MY EYES MOST AT RISK?
As a general rule of thumb we know that UV levels are greatest in the middle of the day when the sun is at its highest, i.e. Between 10am and 2pm. So, it’s reasonable to conclude that this is the time of day where sun protection is most important, and this is when you would wear sunglasses. However, the rules of UV exposure for the skin and eyes is actually slightly different, because not only are our eyes affected by direct UV, but also indirect UV reflected off objects and surfaces (water reflects 25% UV and snow reflects 80% UV!).
In 2011 a Japanese study showed that the peak UV exposure for our eyes occurred at a time when the sun is at a low enough level that not only are we exposed to the direct rays but also light entering the eye from an indirect path. They found this timeframe to be between 8-10am and 2-4pm, when the sun sat at about 40°. As you can imagine, this peak exposure is occurring at a time where people are less likely to be wearing sunglasses, especially if it isn’t a particularly bright day.
NOT ALL SUNGLASSES ARE CREATED EQUAL!
Most sunglasses claiming “100% UV protection” or “UV400” only reduce UVR transmission through the lens, however we now know that light reflected off the back of our lenses plays a big role too, and in fact 50% of UVR penetrating the eyes is caused by these back-surface reflections. This is especially important for spectacle wearers, because research shows that 84% of us will turn away from bright sunlight, thus creating an opportunity for UVR to be reflected off our glasses, increasing our exposure.
At Eyes of Howick Optometrists we want to offer the highest level of protection to our patients, and that’s why we have partnered with Essilor. Only Essilor lenses have been approved by the Cancer Society for their UV protecting properties, and their Crizal coatings help to further shield your eyes from UVR by blocking those harmful back-surface reflections.
E-SPF:
To make things easier for the consumer, Essilor scientists have also developed the E-SPF (Eye-Sun Protection Factor) index. This certifies the global UV protection your lenses provide your eyes as well as the delicate skin that surrounds them, and provides a means for optometrists and patients alike to compare the level of UVR protection in their eyewear in the same way they would with sunscreen. As with SPF in your skincare, the higher the E-SPF the greater the protection.
WHAT ARE MY OPTIONS?
· Sunglasses
Aside from blocking direct light with a hat or shade, sunglasses are an obvious first choice. Look for larger frames with a bit of wrap that will provide more coverage and thus more protection. Sunglasses are available in a wide range of prescriptible styles as well as Fitovers (to wear over your prescription glasses), and in a range of colours and tints to suit your needs.
Our Crizal Sun UV Sunglasses and Xperio Polarised Sunglasses offer an E-SPF 50+.
· Transitions
Photochromic lenses are “smart lenses” and change their appearance in response to UV light, being fully clear indoors and darkening outdoors to behave like sunglasses. They block 100% UVA/B and the newer generation Gen8 Transitions released in 2020 activates up to 30% faster than Gen7 and has a 3min faster fadeback!
Gen8 Transitions has an E-SPF 25, and when incorporated with the Crizal Sapphire UV coating has an E-SPF 35.
· UV-blocking clear lenses
While sunglasses play an important role, it’s equally important to make sure that your normal glasses are protecting you as well because there will be times when it isn’t practical to wear sunglasses, or times when it may feel too dull to wear them; But even on an overcast day we are still exposed to UVR. This is when we need to make sure our regular spectacles are doing a good job of protecting our eyes.
Crizal Sapphire UV provides best-in-class UV protection, with an E-SPF 35. That’s 35x more protection than wearing nothing at all and is the gold standard in UV protection for clear lenses. At Eyes of Howick we put this coating on all prescription eyewear, so you can rest assured your eyes are protected when wearing your glasses.
It’s never too early or too late to start thinking about UV protection. Children’s eyes in particular have clearer lenses, allowing more light to enter the eye and making them more susceptible to UV damage. And whilst we encourage use of sun protection year-round, as we approach the summer months and start to spend more time outdoors this will become even more important.
If you’re interested in learning more about how to best protect your eyes from the sun get in touch with us today.