Sunscreen: a user's guide

Applying sunscreen is one of the best ways to protect your skin from the harmful effects of the sun's ultraviolet (UV) radiation. But how much do you know about the stuff? And are you putting it on the right way so you get the full benefits of its protection? Before you slather it on, read these 5 sunscreen facts.

Sunscreen ingredients can go bad. Sunscreens definitely have an expiry date. The expiry date may be 2 or 3 years from the day you purchased it, but always check the bottle. How can you tell if the sunscreen ingredients have gone bad? Try spreading some on your skin – does it seem to thin, too thick, or too clumpy? Has it developed a gritty texture? If your sunscreen seems "off" in texture, it may be a good idea to throw out that bottle and purchase a new one.

Sunscreen ingredients work in two different ways. The ingredients in sunscreens literally shield your skin from the sun's damaging UV radiation. Some elements – known as physical ingredients – reflect the light or cause it to bounce and scatter. Other elements – chemical ingredients – absorb the light into themselves. Either way, your skin is protected. Many formulas make use of both types of ingredients, often called "broad spectrum" sunscreen, and this is the type often recommended for people to use. For those with sensitive skin, there are chemical-free formulations available that contain only physical ingredients like zinc oxide or titanium dioxide.

Sunscreen labels may not tell the whole story. Scanning a sunscreen label, you may see a lot of acronyms – like SPF, UVA, and UVB. Here's a breakdown for you:

  • UVA is the radiation from the sun's light that penetrates into the skin and causes the changes that make your skin appear darker, or tan. UVA waves are usually to block harder than UVB radiation.
  • UVB is the radiation from the sun's light that is responsible for the surface redness and pain of sunburn. Both UVA and UVB are associated with skin damage, skin cancer, and premature skin aging.
  • SPF stands for "sun protection factor." It only measures how much the sunscreen protects your skin from UVB radiation – the sun's light that will cause sunburn. The SPF represents how many times longer you can be exposed to the sun before getting burnt. So say that someone with exposed skin with no sunscreen starts to burn after 2 minutes. That same person wearing SPF 15 sunscreen would be able to be exposed to the sun for 30 minutes (15 times 2 minutes) before burning.

Sunscreen labels always list SPF but not always how well a sunscreen will protect the skin from UVA radiation. Others have suggested changing SPF to SPF-UVB so consumers can make the distinction. Still others say that since high-SPF sunscreens would block most UVB and UVA radiation, it might not be necessary to label it separately.

Sunscreens can be ineffective. This is different than when a sunscreen's ingredients go bad. No, this is when you just don't use it correctly. Certain situations make sunscreen less protective:

  • When you sweat: When you perspire, sunscreen may slough off your skin. In humid weather or while exercising, you may need to apply more sunscreen more often to make up for loss when you sweat.
  • When you get wet: No sunscreen is truly waterproof. And even "water-resistant" formulas will need to be reapplied after going swimming or taking a shower.
  • When you dry off: Any time you wipe down your skin with a towel, you might rub off all of your sun protection.
  • When you don't reapply: No sunscreen lasts all day. Whether it's sunny or overcast, you need to apply sunscreen 15 minutes to an hour before you'll be outdoors and then reapply it every 2 hours.
  • When you don't use enough: Dermatologists recommend "liberal" use of sunscreen. That means about 1 ounce or 2 to 3 tablespoons per application – which is about enough sunscreen to fill a shot glass. Rub it in evenly across all parts of your body that will be exposed to the sun. Don't forget forgettable spots, like your hands, your feet, the backs of your ears, the back of your neck, your knees, and bald spots on the head.
  • When you don't use it at all! Sunscreen is not just for sunny days. 80% of the sun's UV radiation makes it through the clouds, and snow reflects the same amount. UVA rays can even pass through office windows! The American Academy of Dermatology suggests daily sunscreen use on any parts of your skin that clothing won't cover (hands, face) on any day you will be outside.

Sunscreen comes in many varieties. You're ready to hit the pool or head out to the beach, and you figure you'll stop by the drugstore to grab some sunscreen. Smart – but browsing the sunscreen section can be surprisingly challenging! You have many choices: lotion, gel, spray, creams, sticks, and others. Which do you choose? As long as you choose a sunscreen that is water-resistant with broad-spectrum protection and an SPF of at least 30, the rest is up to personal preference. Consider a cream if you have dry skin, and opt for a stick sunscreen to apply around sensitive spots like the eyes.

Amy Toffelmire

All material copyright MediResource Inc. 1996 – 2022. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source:

Stay safe at the pool and the beach

A day at the beach or the pool should be fun and carefree. You'd like to be able to bury your worries beneath the sand, slip on your swimsuit, and jump right in. But when you dip your toes in public waters, you expose yourself to all sorts of potential health hazards. A bit of care and caution is all it takes to enjoy a safe day in the sand and surf.

What do you do in the water?

Accidental drowning is the most obvious safety hazard around water. At a pool or major beach swimming area, you may have the added security of trained lifeguards, but you should still keep your (sunglass-covered) eyes peeled. And you should always adhere to any signs posted by the open water or pool – they are there for everybody's safety.

  • Be on guard. Reduce risk by supervising young or inexperienced swimmers. Swim lessons can boost the skills and confidence of children and adults alike.
  • Go with the float. Life jackets and other kinds of flotation devices buoy inexperienced or unconfident swimmers.
  • Avoid troubled waters. Watch out for possible danger zones in open waters – undertows and rip currents, tangles of seaweed that could wrap around your ankles, or sudden drops in depth can surprise even the strongest swimmers. Be cautious of wildlife in the area, too. Sharks, jellyfish, stingrays, or other creatures pose threats to swimmers.
  • Booze off. Much as you'd love to sip a frosty daiquiri as you float along, water and alcohol don't mix well. Alcohol impairs motor function and judgment – two faculties you need intact whether you're wading or jet-skiing, paddling or hanging your feet from the side of a pontoon boat.

What's in the water?

Depending on what sort of waters you plunge into – chlorinated or natural, salty or fresh – you're bound to pass through some stuff that's not too healthy. Open, natural waters can be home to many kinds of microbes. Public pools can harbour bacteria such as Giardia lamblia and Campylobacter, and protozoa like diarrhea-causing Cryptosporidium. Harsh chemicals (e.g., chlorine) meant to keep the pool cleaner can actually irritate the skin and lungs. Though it's less likely in a well-maintained pool, bacteria, viruses, and fungus can all survive even in chlorinated waters.

  • Don't drink the water. In both natural areas and in outdoor pools, water can be teemed with traces of human and animal fecal matter and lots of chemicals and other yucky stuff you'd rather not be drinking. It's not like people sip pool water to quench a thirst; it just happens sometimes.
  • Teach your children well. Kids gulp down more water than adults as they swim, so talk to your child about the importance of keeping their lips sealed as they swim.
  • Swim safely in the ool. Note how there was no "p" in pool? It should stay that way, but too often urine finds its way into pool and open water.
  • Be easy on the ears. Water can flow into your ear and get trapped inside the ear canal. When this happens, a painful infection called swimmer's ear can result. Bacteria from unclean water could make this kind of infection more likely. Rather than using cotton swabs to clear out water, you can use a blow dryer set on low while you’re drying your hair.
  • Use your best judgment. Unsafe or unsanitary waters should be marked with warning signs. If you're unsure about the safety of a swimming area, it's best to stay out of the water.

And this sun, sand, and surf tip cannot be mentioned too often: always protect your eyes and skin from sun damage. Wear UV-shielding sunglasses and slather on sunscreen with an adequate sun protection factor (SPF), reapplying as necessary and every time you get out of the water.

Amy Toffelmire

All material copyright MediResource Inc. 1996 – 2022. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source:

8 tips for choosing sunglasses

We can't see ultraviolet light, but at least now we know it's there, and we know that we should protect ourselves from it. Up until the 1930s, sunglasses weren't widely available. Protecting our eyes from the sun meant wearing a wide-brimmed hat. Nowadays, we know that ultraviolet (UV) radiation can lead to serious eye damage, including cataracts, cancer, snow blindness, and more commonly, photokeratitis, which amounts to an eye sunburn. Ouch.

UV radiation from the sun can reach our eyes in many ways – bouncing off water, clouds, snow, and the windows of buildings and passing cars. And not all of the sun's light affects our eyes in the same way. 95% of all of the UV radiation that reaches the Earth's surface are UVA rays; the other 5% is UVB radiation. The outer layers of our eyes act like natural sunglasses, shielding our retinas from most UV radiation: UVB is fully absorbed by the cornea of the eye, and UVA passes through the cornea but is filtered by the lens of the eye. Only about 1% or less of UV radiation actually reaches the retina.

Although UVB is the type of radiation associated with eye damage, UVA can also play a part (e.g., in the formation of cataracts). In general, UVA or UVB protection is required as neither has proven to be good for our eyes.

Staying out of the sun during the peak UV hours of 11 am to 3 pm is not always possible. And wearing a hat provides minimal protection, as do regular eyeglasses. To best block out the harmful UV rays, your eyes need more protection.

When you're shopping for sunglasses, consider these 4 things that matter:

  • Numbers matter. When shopping for sunglasses, look for labels that say the lenses block out 99% to 100% of UV radiation. Make sure they block out both UVA and UVB rays.
  • Fit matters. Poorly fitted sunglasses may not provide enough protection. You may be less likely to wear glasses that feel awkward or uncomfortable. Consider sunglasses with wider lenses for better protection. Athletes have the right idea with wraparound sunglasses.
  • Lenses matter. Polarized lenses deflect glare but don't offer UV protection. Lenses made from real glass provide little protection at all. Your best choice these days? Polycarbonate plastic lenses. These tougher lenses provide adequate UV protection and are sturdier than other varieties. Photochromic lenses are also a good option because they block glare and UV radiation while maintaining visual sharpness.
  • Functionality matters. Options exist for those who have a hard time wearing sunglasses. If you wear eyeglasses, try prescription sunglasses, tinting for your eyeglasses, or clip-on lenses with UV protection. New contact lenses are available with enhanced protection, but sunglasses should still be worn.

Okay, now for 4 things that don't matter too much:

  • Age. Children's eyes need even more protection from the sun than adults. But if you take a look around next time you head out to the pool or beach or playground, you'll notice lots of adults wearing sunglasses but very few kids with any eye protection at all. Because of their clearer corneas and lenses, children's eyes let in more UV light than the more fully developed eyes of adults and thus are at even higher risk of sun damage. Many sunglasses manufacturers offer kids' styles. Let your kids pick out whatever fun frames they'd like, but just make sure to choose a pair with 99% to 100% UV protection.
  • Season. Our eyes need sun protection all year long, so don't wait for summer to shop for sunglasses. During the fall and winter, you may see the sun less often, but that doesn't mean its effects aren't felt by our eyes. Sea foam, beach sand, and snow: they all reflect damaging UV light into our eyes. In fact, winter snow reflects much more UV light than dry sand.
  • Lens colour. For the most part, the colour of lenses in sunglasses shouldn't make a difference in protection. Shades with super-dark lenses may work for celebs wanting to go incognito, but dark lenses provide no extra sun safety. Sunglasses with amber-coloured "blue-blocking" lenses may block out visible blue light (which may damage the retinas ), but they don't provide adequate defence against UV radiation.
  • Cost. Spending more won't necessarily buy you superior protection. Lots of people shell out a bundle for designer shades, while others go cheap and hope for the best. Instead, just look for labels that say the lenses block out 99% to 100% of UV rays.

Amy Toffelmire

All material copyright MediResource Inc. 1996 – 2022. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: