De-mystifying Sunglasses

When it comes to sunglasses and ocular protection the choices can feel overwhelming. Tints, coatings, and styles – with so many options you may not know where to start. Let’s take this opportunity to de-mystify things and offer a little clarity. What do you need to know about choosing sunglasses?

Ultra Violet Light

Let’s begin with making sure your eyes are as well protected as possible. Ultra Violet light is invisible to the naked eye, but its’ effects on the human body can be some of the most harmful.

Linked to cataract development – a hardening of the crystalline lens that can eventually lead to blindness – UV radiation is part of the light spectrum and is found up to 400nm. Well below the visible light spectrum, this is the same radiation that causes sunburns and leads to skin cancer.

The UV threat to your vision is compounded when you wear sunglasses without full UV protection as the tinted lens of the sunglass causes the pupil to dilate as it does at night and allows more of the harmful rays into your eyes.

Clearly job one of any pair of sunglasses is to protect you from this invisible, pervasive threat. Always look for full UV protection when purchasing prescription or non-prescription sunglasses.

Wrap And Sport Sunglasses

Once upon a time, these styles were solely the domain of the non-prescription crowd. The challenge of wrapping a prescription while maintaining vision was a monumental task that all too often ended with poor vision in the periphery and unwearable eyewear.

But as is often the case, technology has significantly improved and new computer-generated lenses are able to meet the challenge making these styles a viable option for those with prescriptions.

These sporty sunglasses are often made with impact resistant lenses to offer safety as well as sun protection and can be tailored to a wide range of sports and activities.


Polarized lenses offer great vision by removing reflections off surfaces. Whether the glare from the water or off the fresh powder on the ski hill, these lenses only allow light to enter the eye directly and thereby offer enhanced clarity and visual acuity.

They usually come in a set colour and can’t be made darker or lighter, but most find the glare reduction properties more than make up for this. The only real challenge with these lens designs comes from some of the visual effects produced by the absence of reflections.

In some instances displays are harder to read, which is why they’re historically not an option for pilots, and when driving they allow the wearer to see the tempering on the back window of other cars. However, overall, they are considered one of the best options for sunglass lenses.


Mirror coatings also offer reflection and glare reduction by reflecting light rays away from the eye as well as reducing the amount of overall light that passes through the lens by 10 to 60%. Additionally, they are also highly valued for their cosmetic properties and visual appeal.


There are a nearly endless variety of colours and shades that can be used for sunglasses but in general the three most popular colours are grey, brown, and green.

The purpose of a tint is comfort and most people have their preference on the colour they like the best, but in reality there is no right or wrong answer.

  • Grey lenses are typically the densest of the colours offering the greatest reduction in squinting from the afternoon sun. They are the most neutral of the lenses and keep the colour you see the truest. Some find the reduction of light to the eye makes them almost too dark for comfort.
  • Brown lenses are slightly amber in colour. They allow a greater amount of light through to the eye and they heighten contrast, making things like street signs stand out better. They do give things a brownish hue that some people find distracting.
  • Green lenses fall between the brown and the grey. Almost as dense as the grey tint, they still offer some contrast enhancement like the brown lens does while turning the world slightly green instead of amber. They have often been the choice of pilots who required the best of both lenses.


Whether prescription or non-Rx, sunnies are a great addition to your vision care. They offer protection from the harmful rays of the sun while allowing you to see clearly and without quinting. Whatever option you prefer, the key to great sunglasses is UV protection.

Talk to your Licensed Optician about your options and find out how to protect your eyes and look great doing it.

Derick Summers
R.O Freelance Optician and Trainer