How to Choose Sunglasses for Summer

  • 21 October 2013
  • Troy Cassidy

This is a great time of year.  There are flowers out everywhere, the days are getting longer, the weather is getting warmer and there's a feeling that summer isn't too far away.  Summer brings it's own dangers, however, and it's important to protect ourselves from the onslaught of UV radiation that NZ gets during the summer months.

UV radiation causes or contributes to a number of eye health problems.  These range from minor degenerations such as pingueculae and pterigia (below), through to serious sight-threatening conditions such as cataract and macular degeneration, to life-threatening conditions like choroidal melanoma.

Pterigium caused by UV exposure over years


The best way to prevent UV damage to your eyes is to avoid being outdoors during the hours when the sun is at its hottest and UV levels are at their highest.  This is normally between 11am and 2pm.  When you are outdoors, wear a wide-brimmed hat to shade your face and eyes.

For direct eye protection, invest in a good-quality pair of sunglasses.  Good sunglasses will not only protect your eyes from UV radiation, but will also make your vision much clearer and more comfortable in the glare of summer.

Here's what to look for when buying sunglasses:

UV RATING: Ensure the lenses block at least 99% of UVA & UVB radiation.  If you are wondering about the protection offered by your sunglasses, feel free to come into Cassidy Eyecare.  We have an instrument which can check the tint density and UV rating of your sunglasses in just a few seconds.

LENS TINT: To be effective at blocking glare, sunglass lenses should block between 70% and 85% of visible light.  Grey lenses give truer colour vision through the lens, while some people prefer the warmer tone of a brown lens. 

LENS CLARITY: Good quality lenses are stable, with no distortions visible in the lens.  A distorted lens may still offer good UV protection, but can cause tired eyes or headaches. 

POLARISED: Polarised lenses block light reflected from horizontal surfaces.  If you've ever driven while the sun glares off a wet road, or been out on a boat on a sunny day, you'll know just how badly reflected glare can affect your vision.  Polarised lenses are amazing at combating glare.

SIZE & FIT: Ensure the sunglasses are big enough to prevent too much light coming in over the top or around the sides.  A comfortable fit will make wearing your sunglasses much more enjoyable.

PRESCRIPTION: If you normally wear prescription glasses, it is possible to produce sunglass lenses to suit your prescription.  These can be made in both polarised and non-polarised forms, and can be glazed into a normal sunglass frame.  My patients LOVE these!

FRAMES: The quality of a sunglass frame doesn't directly affect the protection offered by a sunglass.  However sunglasses with better quality frames will last longer, stay in shape better and be more comfortable than poor-quality sunglasses.  It's also a good rule of thumb that sunglasses with good quality frames tend to have better quality lenses.

Sunglasses are an investment in your eye health.  You don't need to spend a fortune to get great protection, but you're likely to get better protection, comfort and durability by spending a few more dollars than you would on a pair from the service station.  At Cassidy Eyecare we recommend Bill Bass sunglasses as a good starter option: 100% UV blocking polarised lenses, and well-made frames for just $99.  Ranges from Adidas and Oroton are also available.

Happy shopping!



About Troy Cassidy

Troy graduated from the University of Auckland Optometry programme in 1995, and has worked in optometry practices in NZ, Australia & the UK since then. Along with wife Stephanie, he has owned and operated Cassidy Eyecare in west Auckland since 2010.

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