Wellness Wednesday: Eye Safety During a Total Eclipse

A couple weeks ago, in our Wellness Wednesday post called UV Safety and Eyesight, we shared information about how the sun can cause damage to your eyes if you do not protect them. Hopefully, by now, your mom has recovered from your telling her she was right about not looking directly at the sun.

Total Eclipse 2009 in China
Total Solar Eclipse seen in China, 2009

This post is all the more timely because next Monday, the U.S. will experience its first total eclipse of the sun in over 38 years. I’m sure by now you’ve heard all about it. Maybe you’re even tired of hearing about it … or you figure it doesn’t affect you.

Maybe it won’t. If you are not the least bit curious and have no desire to watch one of the coolest natural phenomena in the universe, then that’s fine … you can stop reading now.

Still there?

Good. This means you’re either a little curious or you have nothing else to do at the moment. Whichever one is fine. We are not judging. And hopefully while you’re reading you will even learn something in the process.

What is a Total Solar Eclipse?

infographic-solar-eclipse-facebook.pngSo, we know the Earth spins on an axis, like a top—giving us night and day. It also revolves around the sun in an elliptical orbit once per year—giving us seasons (with a few exceptions). The moon orbits the earth once every 27.323 days, giving us the different phases from new moon to full moon.

During a Total Solar Eclipse, the moon’s orbit crosses paths directly in front of the sun in such a way that from specific areas of the planet, it blocks the sun from view either partially or completely, causing a brief period of darkness in the middle of the afternoon.

total-solar-eclipse-process
Copyright: NASA/Phil Hart

On this occasion, the ‘path of totality’—where viewers will experience a total solar eclipse—cuts diagonally across the U.S. through several states from Oregon down to South Carolina. This means, from those areas, the sun will become completely ‘eclipsed’ by the moon for a brief period on Monday afternoon.

For those of us who are above or below those areas, we will experience a partial eclipse of the sun by the moon. So part of the sun will continue to be visible. But much like the phases of the moon, we will see a waxing and waning effect.

So what’s the big deal?

Well, hopefully, you at least find that a tiny bit fascinating!

Totality2010-S&T-DennisDiCicco
Totality as seen from Easter Island on July 11, 2010. Credit: Dennis di Cicco / Sky & Telescope

But even if you’re not yet sold, if you plan to watch this phenomenon take place or anticipate that your friends might drag you with them to watch … you need to be prepared.

There are many superstitions around total eclipses. But the concern isn’t with the eclipse itself. It doesn’t make people go mad. The sun doesn’t suddenly emit any special rays that are extra harmful. Pregnant women have nothing to fear. You may feel the temperature drop a little for that short time, but it will be brief and no different than just after dusk.

The issue comes when your relaxed eyes are gazing at a covered sun and suddenly it begins to peek back out from behind the moon.

You know what it’s like when you turn on the bathroom light in the morning after your eyes have been in the dark all night long? Ouch! It takes a while to adjust, right? Your dilated eyes need time to constrict and not take in so much light at once.

In an eclipse, this is a similar effect but multiplied by like a million and dangerous because of the UV radiation! When you are typically outside on a sunny day, even without sunglasses (though that isn’t recommended), your eyes adjust, you squint, you look away from the sun … because it is uncomfortable! It’s a reflex. So you are never getting that full on effect of looking at the sun.

During a total solar eclipse, people are purposefully gazing in the direction of the sun and as it begins to peak out from behind the moon, even for a few seconds, that can cause catastrophic damage to your eyes. In the partial phase, visible light is reduced enough that it’s no longer painful or uncomfortable to look at, so people assume it’s safe. And one of the problems is you may not even realize you have done damage until the next day.

WomanShades-MarkMargolis
Credit: Michael Bakich

Exposing your eyes to the sun without proper eye protection during a solar eclipse can cause ‘eclipse blindness’ or retinal burns, also known as solar retinopathy.

You must wear protective eyewear (or you can make a pinhole projector) if you are going to watch any part of a solar eclipse! Sunglasses are not protective. You shouldn’t be able to see anything through a safe solar filter (ISO 12312-2 compliant) except the sun itself.

At this late stage, finding eclipse glasses is getting harder but it’s not impossible. Some libraries are giving them away, or you may still find them at local Best Buy or Lowes stores. You can also try online, but make sure you order from a reputable company and they specify they are ISO 12312-2 compliant.

Witnessing the Total Solar Eclipse

If you are in the path of totality, the moon will begin to cover the sun. Your eyes must be protected. Once the sun is completely blocked by the moon, you can take them off to view this amazing phenomenon. But be brief. This will only last minutes. Be ready to put your glasses back on because as soon as the sunlight begins to appear again, you will need to put them back on.

NASA_map_508.jpgIf you are not in the path of totality, you will only be seeing a partial eclipse. Therefore, you will need to keep your eclipse glasses on for the duration of the event.

When and Where to Watch the Total Solar Eclipse

The actual timing of the eclipse is determined by where you are in the U.S. It can be anywhere between 10:20 a.m. on the West Coast and 2:40 p.m. on the East Coast. Check the NASA website or your local news stations for exact times.

PhilaEclipse
Timing of the Total Solar Eclipse in the Philadelphia, Pa., viewing area.

If you cannot get outside to experience the solar eclipse or you do not have the protective eyewear to do so, many networks are live broadcasting the event, and there will be live streams from NASA as well.

Sources:

American Academy of Opthalmology, American Optometric Association, American Astronomical Society, NASA and Space.com.


More Information:

NASA Eclipse Live Stream [August 21, 12-4 p.m.]

How to safely watch a solar eclipse

Eclipse Across America

How Sunlight Damages the Eyes

WHO: The known health effects of UV

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Wellness Wednesday: UV Safety and Eyesight

Mom probably told you a lot of things growing up that may have seemed silly. “Keep making that face and it’ll freeze that way!” and “Don’t look at me with those eyes!” And, of course, coming back with a retort, like “These are the only eyes I have,” was never in your best interest.

Female EyesBut the truth is … they really are the only eyes you have. And if you ever heard her tell you “Don’t stare into the sun, you’ll hurt your eyes,” you can thank her for that one because she was absolutely right.

We already know ultraviolet (UV) rays can damage our skin, cause wrinkles and skin cancer (melanoma). But did you know it can also damage your eyes?

Ultraviolet Radiation

There are two types of UV rays in sunlight:

UVA rays cause aging in skin cells and can damage the DNA. They can cause long-term skin damage and are responsible for wrinkles. They have also been linked to skin cancer.

UVB rays have more energy than UVA rays. They directly damage the DNA of skin cells and are the main cause of sunburn. They are the rays most responsible for skin cancer.

Both long- and short-term exposure to UV radiation can harm the eyes, affect vision, and compromise eye health. There are also several eye diseases and conditions caused or aggravated by exposure to UV radiation:

Macular Degeneration

EyeSmartMacular Degeneration (AMD) is caused by damage to the retina over time and is the leading cause of age-related blindness. Extended exposure to UV light increases your risk of developing macular degeneration.

Cataracts

A cataract is a clouding of the eye’s natural lens—the part of the eye that focuses the light we see. UV light, especially UV-B rays, increases your risk for certain types of cataracts. It is estimated that 10% of all cataract cases are directly attributable to UV exposure.

Pterygium (surfer’s eye)

Often called “surfer’s eye,” pterygium is a pink, non-cancerous growth that forms on the layer of conjunctiva over the white of your eye. UV light from the sun is believed to be a factor in the development of these growths.

Skin Cancer

The skin of the eyelids is very thin. So even if your eyes are closed, you can do damage to your eyes by exposing the lids to the sunlight. Skin cancer in and around the eyelids is also linked to prolonged UV exposure.

Photokeratitis (snow blindness)

Also known as corneal sunburn or “snow blindness,” photokeratitis is the result of high short-term exposure to UV-B rays. Long hours at the beach or skiing without proper eye protection can cause this problem. It can be very painful and may cause temporary vision loss.

Whenever you spend time outdoors, you should wear quality sunglasses that offer UV protection and a hat or cap with a wide brim. To provide adequate protection for your eyes, sunglasses should:

  • Block out 99 to 100 percent of both UV-A and UV-B radiation
  • Screen out 75 to 90 percent of visible light
  • Be perfectly matched in color and free of distortion and imperfection
  • Have lenses that are gray for proper color recognition

Senior woman on beach holding hatIf you spend a lot of time outdoors in bright sunlight, consider wearing wraparound frames for additional protection from the harmful solar radiation.

And never, ever look directly at the sun. Looking directly at the sun at any time, including during an eclipse, can lead to solar retinopathy, which is damage to the eye’s retina from solar radiation.

So, go thank your mom and tell her she was right!

Sources:

American Academy of Opthalmology, American Optometric Association and the Skin Cancer Foundation.


More Information:

People With Increased Risk of Eye Damage from UV Light

Winter UV Eye Safety

How to Choose the Best Sunglasses

How Sunlight Damages the Eyes

WHO: The known health effects of UV

Wellness Wednesday: The Dangers of UV Exposure

May is Melanoma/Skin Cancer Detection and Prevention Month, so Mercy Health System encourages you to be safe in the sun.

blazinghotsunExposure to UV radiation increases the risk of developing skin cancer, according to the National Cancer Institute (NCI). Melanoma, the deadliest form of skin cancer, is linked to getting severe sunburns, especially at a young age.

Every year, there are 63,000 new cases of and 9,000 deaths from melanoma—the deadliest form of skin cancer.

Ultraviolet (UV) exposure is the most common cause of skin cancer. A new CDC study shows that the majority of Americans are not using sunscreen regularly to protect themselves from the sun’s harmful UV rays.

In fact, fewer than 15% of men and fewer than 30% of women reported using sunscreen regularly on their face and other exposed skin when outside for more than 1 hour. Many women report that they regularly use sunscreen on their faces but not on other exposed skin.


Skin cancer is the most common cancer in the United States. Yet most skin cancers can be prevented.


What are your family’s risks from exposure to powerful UV rays? Consider these facts and statistics.

The Dangers of UV Exposure

  • You can sunburn even on a cloudy day.
  • On average, children get 3 times more exposure than adults.
  • Concrete, sand, water and snow reflect 85% to 90% of the sun’s UV rays.
  • Depletion of Earth’s ozone continues to increase your exposure to UV rays.

Skin Cancer

  • In some parts of the world, melanoma is increasing at rates faster than any other cancer.
  • More than 1.2 million new cases of skin cancer are diagnosed each year in the US.
  • Melanoma, the deadliest form of skin cancer, kills one person every hour.
  • One blistering sunburn can double a child’s lifetime risk of developing skin cancer.

Visit the American Cancer Society website and take their sun safety quiz to see how much you know about staying safe in the sun.

Source: www.sunsafetyalliance.org


More Information:

Protect Your Family from Skin Cancer

Suncreen: The Burning Facts

FDA Sheds Light on Sunscreens

NIOSH Fast Facts: Protecting Yourself from Sun Exposure

Wellness Wednesday: Indoor Tanning is Not Safer than Sunbathing

ucm399147Exposure to UV radiation—whether from the sun or from artificial sources such as sunlamps used in tanning beds—increases the risk of developing skin cancer, according to the National Cancer Institute (NCI). Melanoma, the deadliest form of skin cancer, is linked to getting severe sunburns, especially at a young age.


“Although some people think that a tan gives them a ‘healthy’ glow, any tan is a sign of skin damage,” says Sharon Miller, M.S.E.E., a Food and Drug Administration (FDA) scientist and international expert on UV radiation and tanning.


“A tan is the skin’s reaction to exposure to UV rays,” says Miller. “Recognizing exposure to the rays as an ‘insult,’ the skin acts in self-defense by producing more melanin, a pigment that darkens the skin. Over time, this damage will lead to prematurely aged skin and, in some cases, skin cancer.”

Indoor tanning is not a safe option

basetan_623_806Both UV-B and UV-A rays damage the skin and can lead to skin cancer. Tanning salons use lamps that emit both UV-A and UV-B radiation.

In July 2009, the International Agency for Research on Cancer (IARC), part of the World Health Organization, concluded that tanning devices that emit UV radiation are more dangerous than previously thought. IARC moved these devices into the highest cancer risk category: “carcinogenic to humans.” Previously, it had categorized the devices as “probably carcinogenic to humans.”

IARC concluded that there is convincing evidence of an association between the use of indoor tanning equipment and melanoma risk, and that the use of tanning beds should be discouraged.

“It’s well established that UV radiation from the sun causes skin cancer,” says Miller. “Since lamps used in tanning beds emit UV radiation, the use of indoor tanning devices also increases your risk of skin cancer.”

Other Risks

In addition to the serious risk of skin cancer, tanning can cause:

  • Premature aging. Tanning causes the skin to lose elasticity and wrinkle prematurely. This leathery look may not show up until many years after you’ve had a tan or sunburn.
  • Immune suppression. UV-B radiation may suppress proper functioning of the body’s immune system and the skin’s natural defenses, leaving you more vulnerable to diseases, including skin cancer.
  • Eye damage. Exposure to UV radiation can cause irreversible damage to the eyes.
  • Allergic reaction. Some people who are especially sensitive to UV radiation may develop an itchy red rash and other adverse effects.

Advocates of tanning devices sometimes argue that using these devices are less dangerous than sun tanning because the intensity of UV radiation and the time spent tanning can be controlled. But there is no evidence to support these claims. In fact, sunlamps may be more dangerous than the sun because they can be used at the same high intensity every day of the year—unlike the sun whose intensity varies with the time of day, the season, and cloud cover.

Tanning in Children and Teens

image-20150608-8697-1m0f3g2The FDA believes that limiting sun exposure and using sunscreen or sunblock are particularly important for children since these measures can prevent sunburn at a young age.

NCI reports that women who use tanning beds more than once a month are 55 percent more likely to develop melanoma. Teenage girls and young women make up a growing number of tanning bed customers.

“Young people may not think they are vulnerable to skin cancer,” says Ron Kaczmarek, M.D., M.P.H., FDA epidemiologist. “They have difficulty thinking about their own mortality.”

Yet of the more than 68,000 people in the U.S. who will learn they have melanoma this year, one out of eight will die from it, according to NCI estimates. In addition, the American Academy of Dermatology reports that melanoma is the second most common cancer in women 20 to 29 years old.


Some states are considering laws to ban those under age 18 from using tanning beds. And many states now have laws that require minors to have a parent’s consent or be accompanied by a parent to the tanning facility.


“Parents should carefully consider the risks before allowing their children under 18 to tan,” says Miller.

The Riskiest Practices

The FDA, NCI, the American Academy of Dermatology, and other health organizations advise limiting exposure to natural UV radiation from the sun and avoiding artificial UV sources such as tanning beds entirely.

All use of tanning beds increases the risk of skin cancer. Certain practices are especially dangerous. These include:

  • Failing to wear the goggles provided, which can lead to short- and long-term eye injury.
  • Starting with long exposures (close to the maximum time for the particular tanning bed), which can lead to burning. Because sunburn takes 6 to 48 hours to develop, you may not realize your skin is burned until it’s too late.
  • Failing to follow manufacturer-recommended exposure times on the label for your skin type.
  • Tanning while using certain medications or cosmetics that may make you more sensitive to UV rays. Talk to your doctor or pharmacist first.

Source: http://www.fda.gov/ForConsumers/ConsumerUpdates

http://www.fda.gov/downloads/ForConsumers/ConsumerUpdates/UCM190664.pdf

Wellness Wednesday: Protect Yourself from Skin Cancer

img1Did you know? Skin cancer is the most common cancer in the United States? Yet most skin cancers can be prevented.

Every year, there are 63,000 new cases of and 9,000 deaths from melanoma—the deadliest form of skin cancer.

Ultraviolet (UV) exposure is the most common cause of skin cancer. A new CDC study shows that the majority of Americans are not using sunscreen regularly to protect themselves from the sun’s harmful UV rays.

In fact, fewer than 15% of men and fewer than 30% of women reported using sunscreen regularly on their face and other exposed skin when outside for more than 1 hour. Many women report that they regularly use sunscreen on their faces but not on other exposed skin.

Mom-sunscreenWhat is important to remember is that the sun produces dangerous UV rays, whether it’s sunny or a cloudy day.

UV rays, which can penetrate cloud cover, damage the DNA of skin cells, which causes the melanin in the body to rush to that site and try to compensate for the damage. Melanin is responsible for the pigment (color) of your skin. So when this happens, the skin changes color … pink or red for some, tan or brown for others. Whichever color your skin becomes (sunburn or suntan), both are a result of damaged skin cell DNA caused by ultraviolet rays.

Sometimes this damage affects certain genes that control how skin cells grow and divide. If these genes no longer work properly, the affected cells may become cancer cells. 

Sun Protection Strategies That Work

  • Use broad spectrum sunscreen with SPF 15+ to protect any exposed skin.
  • Seek shade, especially during midday hours.
  • Wear sunglasses, a hat that covers your ears, and other clothes to protect skin.
  • Sunscreen works best when used with shade or clothes, and it must be re-applied every two hours and after swimming, sweating and toweling off.

Sources: American Cancer Society, Centers for Disease Control and Prevention


More Information

Protect Your Family from Skin Cancer

Suncreen: The Burning Facts

FDA Sheds Light on Sunscreens

NIOSH Fast Facts: Protecting Yourself from Sun Exposure

 

Wellness Wednesday: Keeping Little Ones Safe in the Sun

SunSafetyInfantsIt’s beach time! But when you bring your family to the beach, how do you protect your little ones? Sunscreens are recommended for children and adults. But what about babies?

According to Hari Cheryl Sachs, M.D., a pediatrician at the Food and Drug Administration (FDA), infants under 6 months of age should be kept out of the sun.

“Babies’ skin is less mature compared to adults, and infants have a higher surface-area to body-weight ratio compared to older children and adults.” explains Sachs. “Both these factors mean that an infant’s exposure to the chemicals in sunscreens may be much greater, increasing the risk of side effects from the sunscreen.”

Sachs says the best protection is to keep your baby in the shade, if possible. And if there’s no natural shade, create your own with an umbrella or the canopy of the stroller.

“If there’s no way to keep an infant out of the sun, you should check with your pediatrician about what to do for your baby.” If your pediatrician agrees, you can apply a small amount of sunscreen—with a sun protection factor (SPF) of at least 15—to small areas such as the cheeks and back of the hands. Sachs suggests testing your baby’s sensitivity to sunscreen by first trying a small amount on the inner wrist.

Cover Up

The best way to protect an infant in the sun is to keep skin from being exposed. As much as possible, the American Academy of Pediatrics (AAP) suggests dressing infants in lightweight long pants, long-sleeved shirts, and brimmed hats that shade the neck to prevent sunburn. Use a hat with a brim that covers your baby’s neck and ears they don’t shade the neck and ears, sensitive areas for a baby.

Other Challenges

“Younger infants don’t sweat like we do,” Sachs says. “Sweat naturally cools the rest of us down when we’re hot, but babies haven’t yet fully developed that built-in heating-and-cooling system. So you want to make sure your baby doesn’t get overheated.”

“In the heat, babies are also at greater risk of becoming dehydrated. To make sure they’re adequately hydrated, offer them their usual feeding of breast milk or formula,” says Sachs. “The water content in both will help keep them well hydrated.

Sun Safety Tips for Infants

BabyTentHere are some things to keep in mind this summer when outside with infants:

  • Keep your baby in the shade as much as possible.
  • Consult your pediatrician before using any sunscreen on your baby. If you do use a small amount of sunscreen on your baby, don’t assume the child is well protected.
  • Make sure your child wears clothing that covers and protects sensitive skin. Use common sense; if you hold the fabric against your hand and it’s so sheer that you can see through it, it probably doesn’t offer enough protection.
  • Make sure your baby wears a hat that provides sufficient shade at all times.
  • Watch your baby carefully to make sure he or she doesn’t show warning signs of sunburn or dehydration. These include fussiness, redness and excessive crying.
  • Hydrate! Give your baby formula or breast milk if you’re out in the sun for more than a few minutes. Don’t forget to use a cooler to store the liquids.
  • Take note of how much your baby is urinating. If it’s less than usual, it may be a sign of dehydration, and that more fluids are needed until the flow is back to normal.
  • Avoid combination sunscreens containing insect repellants like DEET. Young children may lick their hands or put them in their mouths. According to the AAP, DEET should not be used on infants less than two months old.
  • If you do notice your baby is becoming sunburned, get out of the sun right away and apply cold compresses to the affected areas.

http://www.fda.gov/downloads/ForConsumers/ConsumerUpdates/UCM309579.pdf

Wellness Wednesday: Reducing Your Risk of Skin Cancer

July is UV Safety Month … and for good reason.

Protection from ultraviolet (UV) radiation is important all year round. However, exposure to UV rays from sunlight is the greatest during the summer months.

This is because you’re spending more time outside. You’re near or in the water. And you’re wearing less and/or lighter clothing than in the colder months. So your skin is more exposed to potentially damaging rays.

The sun’s UV rays can damage your skin in as little as 15 minutes. UV rays from the sun can reach you on cloudy and hazy days, as well as bright and sunny days, because clouds block visible light, not UV. Many people don’t realize they are getting too much sun when it is overcast or if there is a light wind.

The hours between 10 a.m. and 4 p.m. are the most hazardous for UV exposure outdoors. UV rays reflect off of surfaces like water, cement, sand and snow. So days spent at the beach or near a pool, are crucial times to apply and reapply sunscreen and take protective measures, such as wearing a wide-brimmed hat.

Suntanners beware. It doesn’t matter that you have that envious olive color skin. You are still damaging your skin. We hear it all the time: “I don’t burn; I tan. So I don’t have to worry.” Wrong!

sunburnWhen your skin is exposed to UV rays, your body makes melanin to try to protect the deeper layers of your skin from damage. Melanin is what gives your skin color. Some people produce more melanin, so their skin is naturally darker.

When your skin is damaged by the sun’s rays, your body’s defense mechanism is to make more melanin to shield your skin cells from additional damage. The melanin absorbs ultraviolet light and causes the skin to change color. Those who produce more melanin will typically tan. Those who are fair-skinned do not produce as much melanin, so instead of tanning, they just burn. But even those who tan can get a sunburn if they spend a lot of time out in the sun.

The result is still that the UV rays are actually damaging the DNA of your skin cells. Once this happens, those cells die and the body’s reaction to this is to begin flooding the area with blood to help with the healing process. And as you can guess, that is what causes the bright red glow of a sunburn.

So no matter which camp you fall in, you should always wear sunscreen before going outside. Here are some additional recommendations to help protect yourself and your family.

  • Stay in the shade, especially during midday hours.
  • Wear clothing that covers your arms and legs.
  • Wear a hat with a wide brim to shade your face, head, ears and neck.
  • Wear sunglasses that block both UVA and UVB rays.
  • Use sunscreen with sun protection factor (SPF) 15 or higher, and both UVA and UVB protection.

Shade

You can reduce your risk of skin damage and skin cancer by seeking shade under an umbrella, tree, or other shelter before you need relief from the sun. Your best bet to protect your skin is to use sunscreen or wear protective clothing when you’re outside—even if you’re in the shade.

Clothing

Enjoying Playing in the Sand TogetherClothes made from tightly woven fabric offer the best protection. A wet T-shirt offers much less UV protection than a dry one, and darker colors may offer more protection than lighter colors. Some clothing certified under international standards comes with information on its UV protection factor.

If wearing this type of clothing isn’t practical, at least try to wear a T-shirt or a beach cover-up. Keep in mind that a typical T-shirt has an SPF rating lower than 15, so use other types of protection as well.

Hat

For the most protection, wear a hat with a brim all the way around that shades your face, ears and the back of your neck. A tightly woven fabric, such as canvas, works best to protect your skin from UV rays. Avoid straw hats with holes that let sunlight through. A darker hat may offer more UV protection.

If you wear a baseball cap, you should also protect your ears and the back of your neck by wearing clothing that covers those areas, using sunscreen with at least SPF 15, or by staying in the shade.

Sunglasses

Sunglasses protect your eyes from UV rays and reduce the risk of cataracts. They also protect the tender skin around your eyes from sun exposure. Sunglasses that block both UVA and UVB rays offer the best protection. Most sunglasses sold in the U.S., regardless of cost, meet this standard.

Sunscreen

swimmingoldermanPut on broad spectrum sunscreen with at least SPF 15 before you go outside, even on slightly cloudy or cool days. Don’t forget to put a thick layer on all parts of exposed skin. Be careful not to forget ears, tops of feet, behind your knees, and other spots that might be exposed. Get help for hard-to-reach places like your back. And remember, sunscreen works best when combined with other options to prevent UV damage.

How sunscreen works. Most sun protection products work by absorbing, reflecting, or scattering sunlight. They contain chemicals that interact with the skin to protect it from UV rays. All products do not have the same ingredients; if your skin reacts badly to one product, try another one or call a doctor.

SPF. Sunscreens are assigned a sun protection factor (SPF) number that rates their effectiveness in blocking UV rays. Higher numbers indicate more protection. You should use a broad spectrum sunscreen with at least SPF 15.

Reapplication. Sunscreen wears off. Put it on again if you stay out in the sun for more than two hours and after swimming, sweating or toweling off.

Expiration date. Check the sunscreen’s expiration date. Sunscreen without an expiration date has a shelf life of no more than three years, but its shelf life is shorter if it has been exposed to high temperatures.

Cosmetics. Some makeup and lip balms contain some of the same chemicals used in sunscreens. If they do not have at least SPF 15, don’t use them by themselves.

Sources: Centers for Disease Control and Prevention, American Academy of Dermatology


More information:

Sunscreen: The Burning Facts
U.S. Environmental Protection Agency (EPA)

FDA Sheds Light on Sunscreens
U.S. Food and Drug Administration (FDA)

Protecting Yourself from Sun Exposure
National Institute for Occupational Safety and Health (NIOSH)