Sunscreen can be greasy and disgustingly goopy, yet many wouldn't think of spending long periods in the sun without slathering it on to protect skin from harmful rays. Meanwhile, sunglasses can be funky, stylish and easy to wear, yet not everyone - and notably youngsters - can be bothered to grab a pair as they head outside. But just because eyes don't turn red and blister like overexposed skin, it doesn't mean that health consequences aren't accumulating over long stretches of time.
"As a general rule, I think most eye-care practitioners - optometrists and ophthalmologists - would agree that the general population, if they're going to be outside in the sun for any length of time, need to have some kind of protection," says Ralph Chou, an associate professor in the school of optometry at the University of Waterloo.
"In terms of long-term exposures, what you find is that there are a number of eye conditions that occur later in life that seem to be either encouraged or triggered by lifelong exposure to ultraviolet.
"The things that we're thinking of would include problems like cataracts, which is a clouding of the lens inside the eye. Also possibly the development of macular degeneration, which is for a western society probably the No. 1 cause of vision loss in an otherwise healthy senior population."
Dr. Lorne Bellan, head of ophthalmology at Misericordia Health Centre in Winnipeg, agrees that ultraviolet light can predispose someone to cataracts and macular degeneration, but says it does take a fair bit of exposure to make a difference.
"If you're just going out - zipping outside for a couple of minutes - it's not like you have to put sunglasses on to be protected, otherwise horrible things will happen," he says.
A study of East Coast fishermen in an area around Boston showed the benefit of sunglasses, he says. The rate of cataracts was noticeably higher in those who did not wear sunglasses versus the ones who tended to wear them all the time when they were outside.
Deborah Gold, director of research at the CNIB, also notes that prolonged exposure over a lifetime is the issue.
"So younger kids, teens, people in their early 30s, these are all important times to wear sunglasses, and a hat with a brim and protect from those rays because it's a cumulative effect," she says.
The CNIB has declared Thursday, May 27 to be Shades of Fun day.
"We're asking Canadians across the country from coast to coast to put on their sunglasses for the day," Gold says.
"This would be even at work, even indoors; just make a statement that you care about your eye health."
Chou says that estimates from various sources suggest that the typical North American probably gets close to 50 per cent or maybe more of their total lifetime exposure to ultraviolet radiation sunlight before they turn 18.
When purchasing sunglasses, there are a few things to bear in mind, including UV protection, lens colour, polarization, fit and wearability. Beyond that, if the buyer isn't happy with the style and how they look - well, they probably won't get worn.
Chou says most adults are looking for sunglasses that will make vision more comfortable for a variety of activities. For driving, it's important to be aware of how certain colours of lenses might affect the ability to identify traffic signals.
"As a rule, what we recommend to patients is that they choose sunglasses that have either grey, brown or greyish-green lenses because those tints will generally not create problems with colour vision," he says.
Occasionally, he says advertisements talk about how yellow lenses enhance vision, and they do indeed seem to make vision a little bit sharper - but it will come at the expense of being easily able to tell yellow and green traffic signals apart.
"Yellow lenses actually are often used by people who are doing outdoors target shooting because it just sharpens their vision. It makes it easier for them to see targets in the distance. It's a specialty application. ... if they want to use the same lenses to drive to the place, that's where the problem arises."
Sunglasses marketed several years ago as "blue blockers" provided more comfortable vision, but someone looking at a green traffic signal might see it as dark grey or black, he adds.
When choosing sunglasses, he suggests that purchasers look at the tint, and take a look at traffic signals out the window if possible to make sure that the colour of the lens is going to be safe for an intended activity, like driving.
As for UV protection, the experts advise checking the tags.
UVB is the shorter wavelength of ultraviolet rays that causes sunburn of the skin and "snow blindness," essentially a sunburn on the front of the eye, Chou says.
"It's a fairly painful condition that goes away after a day or so, but it can be quite uncomfortable."
UVA is what causes the skin to tan. When Chou was starting his career, he says the research community saw it as fairly innocuous.
"In the past 20 years, though, we've changed our minds because what we're finding more and more is that ultraviolet A penetrates deeper into the eye and skin than ultraviolet B does. And its effects are not as immediate, but they are much more deep-seated."
Environment Canada says it has nine sites where it monitors UV levels.
"On average, UV levels over Canada have only gotten marginally higher, with the UV index values in the 2000s at about three per cent higher than they were prior to 1980," the agency said in an email response to a query about UV tracking.
Gold advises making sure sunglasses are 99 per cent protective of ultraviolet rays, and that they cut glare. She's also in favour of wraparound styles because sunlight getting in from the sides can also affect the eyes.
For those spending time on the water, Bellan suggests polarized lenses.
"The water makes a bit of a difference because the light bounces off the water and it comes back a little bit polarized, so there is a slight advantage to polarized lenses when you're doing a lot of water sport compared to a regular sunglass," he says.
In terms of transition lenses, which change colour from clear inside to darker outside, Chou says plastic lenses are better than glass. And some won't darken if you're behind a car window, so it's important to find out if they do before purchasing them.