Most of us know how important sunscreen and hats are for UV protection outdoors, but a decent pair of sunglasses is just as critical. And there's no shortage of options when it comes to buying new sunnies. You can splash out on expensive designer shades, grab a pair from your favourite high-street store, or go for some cheapies at your local chemist or service station. But sunglasses are a preventive health product and not all of them are created equal.

Seeing into the future

Repeated exposure to UV radiation can cause a number of serious (and seriously icky) eye problems, including cataracts, pterygiums (overgrowth of tissue from the white of the eye onto the cornea), solar keratopathy (cloudiness of the cornea), cancer of the conjunctiva, and skin cancer of the eyelids.

And it's just as important to protect children's eyes from the sun with sunglasses (as soon as you can convince them to keep them on); UV exposure in childhood is related to skin problems later in life, and it's likely to be much the same for eyes.

Up to standard

Designer frames can cost upwards of $200, but you don't need to spend a week's salary for a pair of shades that will protect your eyes from glare and, most importantly, UV rays.

All sunglasses sold in Australia must be tested and labelled according to the Australian/New Zealand standard AS/NZS 1067:2003 Sunglasses and Fashion Spectacles.

Look for a lens category of at least 2 or preferably 3. Under AS/NZS 1067:2003, sunglasses and fashion spectacles are classified as one of the following:

  • Lens category 0: Fashion spectacles
    These are not sunglasses, as they have a very low ability to reduce sun glare. They provide limited UV protection.
  • Lens category 1: Fashion spectacles
    Like category 0 lenses, these are not sunglasses; however, they do provide limited sun glare reduction and UV protection. Fashion spectacles with category 1 lenses are not suitable for driving at night.
  • Lens category 2: Sunglasses
    These sunglasses provide a medium level of sun glare reduction and good UV protection.
  • Lens category 3: Sunglasses
    Similar to category 2, these sunglasses provide a good level of UV protection. Lens category 3 glasses also provide a high level of sun glare reduction.
  • Lens category 4: Sunglasses
    These are special-purpose sunglasses that provide a very high level of sun glare reduction and good UV protection. Never wear them while driving.

In addition to the five category classifications above, the mandatory standard also covers the following:

  • Also known as variable tint lenses, photochromic lenses may not be suitable for night driving, depending on their transmittance properties (i.e. their ability to reduce sun glare and level of UV protection).
  • Non-conforming lenses have the ability to alter a person's colour recognition, and in particular the detection of traffic light colours. In some cases these lenses must not be used when driving.

What else to know about buying sunglasses

Wrap-around sunglasses

This style may not always be the most fashionable but they are the safest as they offer more UV protection at the sides of the face (and they do come back into style every once in a while – you'll be ahead of the trend!).

Don't be fooled by a dark tint

Dark lenses don't necessarily provide UV protection.

Polarisation

Polarised lenses are usually more pricey, and do help cut down on glare. But they aren't necessary unless you spend a lot of time outdoors in high-glare situations, such as on the water.

Cost

Sunglasses come at a huge range of price points, from pocket change to hundreds of dollars. It doesn't matter what you spend – if it complies with the Standard and has a lens category of 2 or 3, they'll do the job.