Protect Your Eyes with Polarized Sunglasses
I don’t know about you but I have been eagerly waiting for some sunshine. The bright warm glow that makes everyone so happy has been eluding us here in Burnaby. With the warm sunshine and all the fun outdoor activities that it opens up to us comes the risks of UV damage. We all know that UV causes damage to our skin but what about our eyes? Over exposure to Ultraviolet light can result in eye damage in the form of conditions such as photokerititis, cataracts, pterygium, pinguecula, age-related macular degeneration (AMD) and cancer. Some of these conditions are familiar to us and some less so. Here is a quick rundown of these conditions.
Photokerititis: I think many of us who went through the Canadian school system at some point in our school years had Farley Mowat’s book “Lost in the Barrens” to thank for inadvertently teaching us about photokerititis, also known as snow blindness. After many years, I don’t remember a lot about the story but, I do remember the part where the two boys, who are stranded in the Arctic Tundra, have to build an igloo for protection after they come down with snow blindness following long hours out in the snow on a sunny day. This was my first introduction to this condition which is the closest thing to a sunburn of the eye. Eyes burn approximately three times faster than skin and so the possibility of getting at least a mild case of photokerititis is great. Sufferers experience red eyes, pain, light sensitivity, tearing, and difficulty opening the eyes.
Cataracts: This is the clouding of the eye’s crystalline lens. The crystalline lens absorbs ultraviolet radiation and this absorption by the lens is a contributing factor to the formation of cataracts.
Pterygium and pinguecula: Have you noticed some people have a bump on the white of the eye? Usually it is located in either the nasal corner or the temporal corner of the eye. These are what is known as pterygium or pinguecula. They are sometimes a bit yellowish in colour. These two conditions are different, however to the untrained eye it is difficult to differentiate between them.
Age-related macular degeneration: This is one of the leading causes of blindness in Canada and it is a result of damage or destruction of the cells in the macular area of the retina at the back of the eye. The actual cause of this disease is not totally known but short wave blue light is thought to be a contributing factor. As I mentioned when discussing cataracts, the crystalline lens has absorbed the UV rays and as a result they do not cause as much damage to the retina. However, the shorter wave blue light does reach the retina and is believed to be one of the culprits of this damage which results in the destruction of our central vision.
Cancer: The all too familiar “Big C”. Both the skin around the eye and the eye itself is very delicate and susceptible to cancer. UV exposure increases the chance of developing a wide variety of cancers of the skin or eye.
So, have I scared you into the shadows before our sunshine even arrives in full force?
I think ultimately we just need to be aware of the risks and be smart about preventing exposure. Sunglasses are of course going to be our number one suggestion to prevent exposure to UV radiation. Choosing a style that has good coverage and a close fit is optimal. We look for a fit that will assist in blocking light from the sides, top, and behind, as well as from straight on. We also recommend a lens that offers you a UV filter that covers all three UV radiation ranges UV-A, UV-B and UV-C. This filter is independent of the colour. Additionally, in recent years, we have started to highly recommend anti-reflection coatings on the back surface of the sunglass lenses. The reason for this is to help with the bounce back of light coming from behind. I personally notice a significant difference in vision clarity with this coating as opposed to not having it. The front surface of sunglasses, unlike clear glasses does not need this anti-reflective coating since we are trying to limit or filter the light reaching the eyes and so the reflections bouncing off the front surface contributes to this reduction. Mirror coatings also are a fun fashion choice that increase the amount of light bouncing off the front surface thereby reducing the amount of light reaching the eyes.
Now what about colour? Often that seems to be the only factor contemplated but, as noted, it is just one choice of many that need to be made. There are three main categories for colour: grey, brown and green. The grey is a good all purpose colour. Most notable about grey is that it doesn’t distort colour perception. It provides an even dulling of light intensity and is ideal for those who are most light sensitive. Brown is a colour that increases contrast and therefore is a popular choice to enhance vision perception. Brown is a great choice for many athletes, avid golfers, and for professional drivers. Green is a mix of both. It has the same dulling of light intensity of grey and the slight yellow component to the colour allows for some increase in contrast. Ultimately, colour choice is a personal decision. We suggest you look through the different colours and see which one you like your vision through the best.
The last thing that needs to be thought about with regard to sunglasses is polarized or non-polarized. Usually I get one of two questions when I say the word polarization. Either I get, “what is that” or, “you mean all sunglasses aren’t polarized?” Polarized sunglasses are like having mini venetian blinds in your glasses. It filters glare and only lets horizontal light through the lenses. All light from non horizontal trajectories are filtered. Although many people benefit from polarization, those people who spend significant time on the water benefit the most. As with colour, this is also a personal preference.
Most people generally think that a good pair of sunglasses are an indulgence or a luxury. In light of the damage that can result from UV exposure we believe this is a misconception. Sunglasses should be thought of as a health care necessity. We also believe that they don’t have to be outrageously expensive to be effective. There are economical options from really basic sunglasses to a variety of clip-on styles or over glasses. Your eye health is a priority for us and we invite you to come and talk to us and let us help you protect your precious vision.