How much UV protection should sunglasses provide? What is UV400 ?

We’re always seeing references to UV when looking at sunglasses and ski goggles, but most of us probably put fashion before function when making our initial style selections.

When looking for sunglasses keep an eye out (pun intended!) for those labelled as “UV 400”. Lenses with this level of protection block all light rays with wavelengths up to 400 nanometers. This covers all harmful UVA and UVB rays.

Now for the science bit…

UV light is something we can’t see directly but it forms part of the electromagnetic light spectrum, sitting at the high-energy end along with X-rays and Gamma rays. It’s a common misconception that you only encounter high levels of UV exposure, in sunny areas. This isn’t true.

UV light is all around us, yes there are heightened levels and risks in certain areas of the world naturally, or at certain times of the year in others, but unfortunately you’ll find UV exposure everywhere, even on gloomy overcast days and also in reflected situations like snow, water and sand.

UV light can be broken down into 3 types. It’s good to know what effect each on has on us.

  • UVA light – which ages us.
  • UVB light – which burns us.
  • UVC light – which will kill.

Don’t worry you don’t need to start running for the hills or the lotions with regard to UVC! This particular type of UV is beyond our own atmosphere and we are protected form it by the Ozone layer.

Most people are aware of the damage UVA & UVB can do to our skin, but it’s also important to know how it can affect our eyes. Whilst the body can shield the eyes a little with eyebrows, eyelashes and eyelids that protection is only very limited.  Even squinting only provides a tiny level of relief.

UV light can damage your eyes and cause sight problems such as;

  • Photokeratitis – inflammation of the cornea, ouch!
  • Photoconjunctivitis – inflammation of the conjunctiva, the membrane that lines the inside of your eye socket and eyelids.
  • Cataracts – these look unsightly and prevent light transmission to the retina at the back of the eye.
  • Cancer – sadly needs no introduction.
  • Snow Blindness – (a variation of photokeratitis) is a real factor for skiers due to the high altitude and the percentage of glare (up to 80%) being reflected into the eye. This is a seriously painful problem when it occurs.Brown Eyes Iris Eye Coloring Brown Light Gene

So…..what can we do to protect our eyes from UV?

Firstly the obvious thing to suggest is to stay out of those peak exposure times where possible and wear a hat too.  Nothing new with that piece of sunlight related advice.

Invest in great eyewear – make sure they are blocking 100% of all UVA & UVB light as a minimum! Those that mention stopping “harmful blue or blue/violet light” (another area of the spectrum that can damage) should also be highly prized options.

Some brands, such as Oakley, use a lens product that has UV protection inherent to the material, so those inevitable lens scratches will not impact the level of protection.

Spend a little extra time researching the lens material being used, all good sellers will be aware of the attributes of their brands sold, so ask! The swing tag statement on UV simply isn’t enough in many circumstances but enough to cover relevant initial standards.

Going the extra mile up front with your eye protection will keep you looking good and seeing good!