Article Read Duration 8 min read

UVA rays cause premature ageing of the skin and tanning, while UVB rays are responsible for redness and burning. Both increase your risk of skin cancer. UVA rays penetrate skin especially deeply and cause issues such as dark pigment spots, sun allergy and premature ageing.
Effective protection must filter out UVA and UVB. You can tell the level of your sun protection by looking at its SPF rating for UVB rays and its Broad Spectrum labelling for UVA. 
The Anthelios range from La Roche-Posay offers broad spectrum UVA-UVB protection suitable for even the most sensitive skin.


Do you know the difference between UVA and UVB rays, what SPF measures, the importance of the UV Index or the meaning of broad spectrum? If so, you’re in the minority, with the latest National Sun Protection Survey revealing over 90% of Australians are missing the facts around UV radiation.

It’s a worrying statistic, so to help shed a little light we’ve created this comprehensive guide to understanding UV rays. In addition to explaining the effects of UV radiation – both good and bad, we clear up the UVA vs UVB confusion and explain why daily sun protection is essential, all year ‘round.

Ultraviolet radiation, or UV radiation for short, refers to energy produced by the sun. There are three types of ultraviolet radiation (UVR): UVA, UVB and UVC. Each has a different wavelength and only UVA and UVB, which have relatively longer wavelengths, can reach the earth’s surface.

UV rays only account for 5% of the sun rays that reach the earth, but they are very powerful. There are several kinds. While UVC rays are blocked by the ozone layer, UVA and UVB rays reach the earth and have an effect on the skin.


UVA: A as in "Ageing" or "Allergies"

Occurring throughout the year and even on cloudy days, UVA rays account for 95% of the ultraviolet rays that touch the earth's surface. They are tenacious too as they can pass through clouds, glass and the epidermis.

Unlike UVB which causes sunburn, UVA rays are painless but they are not harmless. On the contrary, they can penetrate deep within the skin to reach the cells of the dermis (skin’s deeper layer). By producing free radicals, they can cause long-term damage and bring about:

  • Photoageing: skin’s support structures (collagen and elastin fibres) are modified resulting in a slackening effect and wrinkle formation.
  • Sun intolerance, commonly referred to as sun allergy (redness, itching, polymorphous light eruption).
  • Pigmentation disorders (freckles, dark spots).
  • Development of skin cancers.

Invisible to the human eye, UV radiation – not to be confused with heat from the sun (Infrared radiation) – cannot be felt by the skin. Therefore, the only way you can ensure your exposed skin is protected is with daily sunscreen application. 


UVB: B as in "Burns" or "Bronzed skin"

UVB rays make up just 5% of the UV rays reaching earth. Unlike UVA, they are stopped by clouds and glass, but they can penetrate the epidermis. They are responsible for tanning, but also sunburn, sun allergy reactions and skin cancers.

UVA and UVB radiation are different types of ultraviolet radiation (energy from the sun), classified by wavelength. Ultraviolet A or UVA rays have the longest wavelength, while UVB rays are medium wavelength. Although shorter wavelength radiation is stronger and more damaging, it is also less effective at penetrating the skin. Therefore, both UVA and UVB are similarly harmful. 


What’s the real difference between UVA and UVB?

Penetrating the deeper skin layers, UVA rays are considered THE major cause of premature ageing, contributing to loss of elasticity, wrinkles, pigmentation and roughness. In fact, up to 90% of visible skin ageing is caused by photoageing (sun-induced ageing) as opposed to chronological ageing.1 
Long-wavelength UVA rays are by far the most prevalent, accounting for 95% of UV radiation that reaches the skin. Activating existing melanin, UVA rays are also those responsible for tanning in the short term. 
Higher energy UVB rays, on the other hand, penetrate the surface layers of the skin and are the major contributor to sunburn. These rays also increase melanin production in the skin, for a delayed tanning effect. 
While UVB exposure has long been identified as the main cause skin cancer, it is now acknowledged both UVA and UVB rays increase skin cancer risk. 


UVA Vs UVB Comparison List

UVA/UVB differences: 

  • UVA accelerates skin ageing whereas UVB causes sunburn & redness.
  • UVA has an immediate tanning effect, whereas UVB has a delayed tanning effect.
  • UVA = ~95% of UV rays reaching Earth whereas UVB = ~5% of UV rays reaching earth.
  • UVA penetrates glass whereas UVB does not penetrate glass.

UVA/UVB  similarities: 

  • Penetrates deeper skin layers 
  • Invisible 
  • Increases skin cancer risk
  • Penetrates clouds 


Long UVA rays: an ever-present and invisible risk

All year round, without realizing it, we are constantly exposed to long UVA rays. This is known as passive exposure. These solar rays can travel through clouds, glass and even the epidermis down to the dermis (skin’s deeper layer).


What are the effects of long UVA rays?

The longer the UVA rays, the more deeply they penetrate the skin. They sometimes cause skin damage which can be irreversible:

  • Pigmentation and color disorders, like dark spots and a grayish complexion.
  • Sun allergies and intolerances: Like all UV rays, long UVA rays can trigger the appearance of redness, spots on the skin and itching.
  • Photo-ageing or premature ageing: Reduction in the skin's elasticity and slackening, which favors the appearance of wrinkles.

Long UVA make up 75% of all UV radiation, so any protection worth considering must provide broad-spectrum UVA-UVB coverage.


Understanding sunscreen protection factors

Choosing the right sunscreen can be a real dilemma! With all the different names, numbers and abbreviations, it's not always easy to find what you need. So what do you need to know to get the best protection?


UVB protection: the SPF system

UVB protection is measured using a system called SPF (sun protection factor). In order to avoid sunburn, you need to choose a high SPF. It is indicated on all sunscreens, and there are four levels of protection: low (factor 6 to 10), medium (15 to 25), high (30 to 50) and very high (50+). But what do these sunscreen SPF numbers actually mean?

Let’s consider an example:
Let’s say Laura is a fair-skinned person who can normally stay in the sun for 10 minutes before burning.

If she applies an SPF of 10, the time taken to burn is multiplied by the sun protection factor of 10, so she will be able to stay in the sun for 10 x 10 = 100 minutes before burning.

But bear in mind that she’d need to apply a generous, even layer everywhere to be protected. As a general rule of thumb, you probably need more cream than you think. A golfball-sized amount for the whole body is a rough guide.


While some skins tan easily, others are more fragile and need a constantly high protection factor. With a high protection factor, your skin is better protected. However, product must be re-applied every 2 hours, or after swimming or intense sweating.

Your phototype is a classification that reflects how your skin reacts to the sun. There are six types:

  • Phototype I: milky skin (redheads), always burns, never tans, many freckles.
  • Phototype II: fair skin, always burns, sometimes achieves a slight glow, many freckles.
  • Phototype III: fair to dark skin, sometimes burns, always tans (medium tan), some freckles.
  • Phototype IV: dark skin, never burns, always tans (dark tan), no freckles.
  • Phototype V: brown skin, never burns, always tans (very dark tan), no freckles.
  • Phototype VI: black skin, never burns, no freckles.

Other reasons you might burn unexpectedly include not applying enough to all exposed areas of skin, not allowing enough time for it to absorb, and failing to reapply every two hours and after swimming or exercise. 

In some cases, however, the redness you’re experiencing might not be sunburn. It could be a reaction to your sunscreen’s ingredients, or a condition known as polymorphic light eruption – caused by a reaction to the sun itself.
The most important thing to remember? Even if you skip the burning phase and go straight to a tan, you are still putting your skin – and your health – at risk.  


What is the best UVA and UVB protection for sensitive skin?

While choosing a sunscreen with a high-level SPF (50+ is the highest SPF in Australia) deserves a pat on the back, for comprehensive protection it also needs to be ‘broad-spectrum’. This is because the Sun Protection Factor (SPF) of a sunscreen only measures its ability to filter out UVB rays and help prevent a sunburn. In the case of an SPF 50+, that means filtering out 98% of UVB radiation.

However, UVA rays – which contribute to ageing and long-term damage – can still penetrate the skin, so make sure you choose a sunscreen that’s labelled as broad-spectrum. 

To stay safe in the sun, you need a sun protection that combines UVA and UVB protection. If you have fair skin with light hair and eyes, you will need high or very high protection (SPF 30 - 50+), whereas you may be able to use a lower protection factor if you have darker skin. If you have sensitive skin, you should use a brand that specifically formulates products suitable for sensitive skin.

For nearly 30 years, La Roche-Posay Dermatological Laboratory has developed a range of sunscreens dedicated to protecting all types of sensitive skin, for both adults and children. With its effective sun protection against UVA and UVB, the ANTHELIOS range offers you protection while maintaining excellent tolerance even on sensitive skin.


Which sunscreen should I choose for my sensitive facial skin?

If you have sensitive skin and are looking for effective daily sunscreen for the face, your go-to option is the ANTHELIOS range from the brand La Roche-Posay. All Anthelios products are suitable for sensitive skin and offer balanced UVA-UVB protection.


Do I even need to wear sunscreen in winter?

If you think sunscreen in winter is unnecessary, think again. The Cancer Council recommends sunscreen be worn any time the UV Index (which measures intensity of UV radiation) is 3 or above. In many parts of Australia, the UV Index reaches 3 or more for the majority of the year – including cooler days. 
Additionally, while UVB radiation is less intense during winter, UVA rays remain present throughout the year at the same intensity. Able to penetrate through glass, they make daily broad-spectrum sun protection a necessity – even if you’re just running errands in the car or sitting by a window.


Recommended by dermatologists: Your skin in safe hands

Available in liquids, milks, gels or sprays, the ANTHELIOS range from La Roche-Posay offers you a wide choice of textures that combine comfort and protection, without compromising on tolerance for sensitive skin. Anthelios respects the needs and specific requirements of each skin type and its products are available in different formats. The combination of high UVA and UVB protection protects you against the immediate unpleasant effects of the sun such as sunburn, but also long-term damage like photoaging.


Apply 20 minutes before sun exposure. Sunscreen is only one part of sun protection so wear protective clothing and seek shade. Avoid prolonged sun exposure. Reapply every 2 hours and after swimming, towelling and perspiring in accordance with directions.


Anthelios XL 50+ Comfort Cream: Very high protection for the face

To go even further in its commitment and offer very high protection against UV rays for sensitive skin, La Roche-Posay has enhanced the formula of its flagship facial protection product by adding an anti-oxidant ingredient.

Baicalin: a recognised anti-oxidant

The new formula of the SPF50+ Cream has been enhanced with an anti-oxidant - Baicalin

Result: skin is effectively protected against UVA and UVB. With the right protection, you and your family’s skin is safe under the sun.

Anthelios Ultra Cream SPF50+: A minimalist formula that is suitable for sensitive eyes

Especially for people concerned by ingredients in suncare products, for the first time, La Roche-Posay creates its most minimalist suncare formulas with no compromise on protection. With up to 12 ingredients fewer than the previous formulas, ANTHELIOS Ultra creates an resistant film on skin that prevents eye irritation due to sunscreen migration. Finally, our offering suitable for use around the delicate and sensitive eye area.

Concerns over products stinging the eyes can lead suncare users to skip the eye area, which is one of the most vulnerable areas of skin to the development of skin cancers. In fact, skin cancers of the eyelid account for 5 to 10% of all skin cancers1. ANTHELIOS Ultra is tested on people with sensitive eyes and contact lens wearers under ophthalmological supervision.

The bottom line? Protection is vital, and it must include the sensitive eye area. With ANTHELIOS Ultra, you can apply product around your eyes with no risk of tears or stinging.


To recap, the best way to protect your skin from UVB and ever-present UVA rays is with daily application of a high-level, broad-spectrum sunscreen. Always read the label and use as directed, and make sure you choose a formula suited to your skin type. 

In the La Roche-Posay Anthelios range of broad-spectrum sunscreens for sensitive skin, that means the non-greasy, easily absorbed Anthelios XL Ultra-Light SPF50+ fluid for normal to combination skin. Anthelios Ultra Facial Sunscreen SPF50+ is nourishing for dry, sensitive skin types, while Dry Touch SPF 50+ contains anti-sweat molecule Airlicium to help mattify oily and acne-prone skin as it protects. All Anthelios sunscreens are non-comedogenic, dermatologist-tested and available in tinted versions. 


How to stay protected against UV

  • Always read the sunscreen label and follow directions for use.
  • Apply 20 minutes before sun exposure.
  • Sunscreen is only one part of sun protection so wear protective clothing and seek shade.  
  • Avoid prolonged sun exposure.  
  • Reapply every 2 hours and after swimming, towelling and perspiring in accordance with directions. 
  • Wear a broad brimmed hat and sunglasses to provide added coverage and protect your eyes from sun damage. 
  • If possible, create extra protection by wearing a long-sleeved shirt and pants. 

Click HERE for information on how to keep children safe in the sun.

1Cook BE Jr, Bartley GB. Treatment options and future prospects for the management of eyelid malignancies: an evidence-based update. Ophthalmology 2001 Nov; 108(11):2088-98.




UVA rays disrupt skin’s inner building blocks such as collagen and elastin fibres. Over time,sun exposure causes a loss of plumpness and elasticity as well as wrinkles. UVB rays also stimulate patchy and irregular pigment production leading to dark spots and a sallow complexion. Globally, these changes in the skin are known as photo-ageing.
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Even on a grey and rainy day, skin is exposed to UV rays that will gradually cause the stigmata of photo-ageing to appear. To fully protect your skin, opt for sunscreen every day, not just when it’s warm and sunny. 
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TRUE. If detected early, 90% of skin cancers are curable. That is why screening is so important between dermatologist visits, to keep an eye on your moles and those of your loved ones.
And of course, make sunscreen a daily non-negotiable to protect your moles and prevent skin cancer.
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Did you


To avoid photosensitisation reactions, dermatologists recommend not wearing perfume on sunny days.


ANTHELIOS is a pioneering player in the suncare market. Its broad-spectrum, very high protection is the result of almost 30 years of advanced clinical research into Suncare and sensitive skin.