Why wear sunglasses?
Sunglasses eliminate solar ultraviolet radiation (UVR), in particular the more-damaging UVB radiation. UV rays from sunlight can damage the retina and the lens of the eye. Too much exposure is linked to conditions like cataracts and age-related macular degeneration.
As the eye cannot see UVR, good quality sunglasses have an important function in blocking UVR. Wearing cheap sunglasses with no UV filters poses an even greater danger than wearing none at all because the pupils will dilate allowing more harmful rays into the eye. Good quality sunglasses will filter out both UVA (a good way of looking at the 'A' is for ageing) and UVB (a good way of looking at the 'B' is for burning). The latter is responsible for causing sunburn and can damage eye tissue with prolonged and unprotected exposure.
Good quality sunglasses should meet the industry standard UV400 rating and all the sunglasses and eyewear we sell meet this standard. They will, therefore, provide the eye with substantial protection against solar UVR, and reducing the amount of UVR that the eye is exposed to over a person's lifetime will be beneficial.
Sunglasses for children
According to a report undertaken by the (UK) College of Optometrists 3 in 4 four parents are risking their child's eyesight by exposing them to bright sun without appropriate protection and nearly a third of parents in Britain do not buy their children sunglasses at all. Following this report, Dr Susan Blakeney, optometric adviser at the College of Optometrists, commented, "I am shocked that so many parents do not ensure that their child's eyes are protected in the sun and am equally astounded to see that of those who do, many are opting for 'cheap and cheerful' over quality. Sunglasses don't need to be expensive to offer good protection but it is important for parents to check that the pair they buy carry a CE mark".
Skiing, walking or climbing at high altitude
For anyone going skiing, walking or climbing at high altitude it's essential to wear good quality sunglasses or goggles because on mountains the sun's harmful ultraviolet rays are easily underestimated, with a high risk of sunburn and ultimately skin cancer and eye cataracts.
Because mountain air is cool, it gives a false sense of security about the sunlight. But the higher the altitude, the greater the ultraviolet (UV) radiation, because there is less atmosphere to screen out the harmful rays. A recent study by Japanese scientists revealed that eyes can receive up to 2.5 times more UV on mountains than at sea level. Even when the eyes are turned away from the sun, they can still get over 85 per cent more UV on snow. This can cause conditions such as snow blindness, which can lead to inflammation and cataracts.
When to wear sunglasses?
• Outdoors, especially during summer when the level of UVR at noon is about three times as high as that for winter. More importantly, the levels of UVB can be as much as ten times higher.
• In open spaces (typically when you are taking part in your sport). In such situations, where there might be little or no shade, you are exposed to direct and scattered radiation from the whole sky. A flat surface like the sea reflects 20% of UVA and UVB, which causes high glare.
• Skiing at high altitude. The harmful effects of Solar UVR increase every 1000m and at 2000m can be 30% higher than at sea level. The high reflection of snow increases the problem.
What does polarisation mean?
Polarised lenses are different to standard sunglass lenses; they have a special film either sandwiched between two other layers of the lens or applied to the front of a lens. What this special film does is eliminate glare off a surface like a pavement, road, water or snow.
Lightwaves from the sun travel in all directions but when sunlight strikes a surface, it becomes concentrated – this polarised light as it is called causes glare. A polarised lens will eliminate this polarised light. The result is the ability to see light in its pure state. Objects will appear more defined, sharper and naturally coloured. Instead of squinting to minimise glare, a polarised lens will allow your eyes to see colours with true clarity.
Because polarised lenses block glare off a surface they are popular with sailing, boating and watersports enthusiasts, fishing enthusiasts, snow sports enthusiasts, runners, cyclists and drivers. When used for fishing a polarised lens means you will be able to see down below the surface of the water.
We have produced a special video on polarised lenses and their benefits - see our 'Video' section top link) to view it.
Polycarbonate is the material favoured by most sports eyewear manufacturers because it's very light and shatterproof / impact resistant; providing a very high degree of eye protection. Unlike glass however, polycarbonate will easily scratch so you do need to take care of the lenses and always keep your sunglasses or eyewear in a case or carry pouch when not in use. Polycarbonate lenses that fall onto a hard surface like a tennis court will easily scratch so it's also a good idea to wear a retainer (also called frame cords and cord grips); these attach to the temples (frame arms) and will stop your sunglases or eyewear slipping off your face when you are mobile and you perspire. We sell a range of cords / retainers in our 'Accessories' section.
Frequently Asked Questions (FAQs)
What does ultraviolet (UV) mean?
Ultraviolet is simply one type of energy that is emitted from the sun. At school we learned about light and the electromagnetic spectrum. The ultraviolet rays are simply a component of that spectrum. Other rays that are emitted include microwaves and visible light.
Why can't we see UV rays?
The only rays of the spectrum we see are visible light. Our eyes simply cannot detect the other rays due to their frequency. However just because we cannot see them does not mean we cannot feel or sense them.
Why is UV protection important?
We are surrounded by UV radiation all the time. The quantity depends on the conditions outside such as direct sun and the clouds. UV rays can be reflected.
What is a nanometer?
A nanometer is simply a unit of measurement. It is equal to one-millionth of a millimetre. Light rays move with a wavelength small enough that this is the most applicable way of measuring them.
Why do we need UV protection for our eyes?
The depletion of the earth's ozone layer has made the need for protection from any of the sun's rays even more important. It is believed, but not proven, that ultraviolet rays cause photokeratitis, which is cancer of the eye.
What do UVA, UVB and UVC mean?
This is a further breakdown of ultraviolet rays within their component of the electromagnetic spectrum. Ultraviolet rays travel with a wavelength of 10 to 400nm. UVA has a wavelength of 320 to 400nm and causes sunburning, UVB travels in the range of 280 to 320nm, causes sunburn and kills bacteria. UVC is from 100 to 280nm and is usually filtered out by the ozone layer.
What does UV400 mean?
This is an optical industry standard. It means that the lenses are made to protect your eyes against UV rays up to 400 nanometers in wavelength.
How do my lenses protect my eyes from UV rays?
A special clear filter that screens out UVR is built into the lenses - with plastc lenses this is part of the injection moulding process so it cannot wear off - the filtering effect on good quality sunglasses is therefore permanent and will not diminish with use.