How do I know which SPF to use?
Sunscreens are available in four different levels of protection: low (factor 6 to 10), medium (15 to 25), high (30 to 50) and very high (50+). The higher the protection factor the better your skin is protected, but it’s important to apply the product thoroughly (be careful not to miss any bits) and to reapply it generously every two hours.
What is the difference between UVA and UVB rays?
UVA rays penetrate the deeper layers of skin. They stimulate the production of free radicals in the skin which cause oxidative stress and can lead to indirect DNA damage (where the free radicals modify cellular DNA over time). UVA rays are most commonly associated with photoaging (premature skin aging caused by the sun). They can also trigger sun allergies such as Polymorphous Light Eruption (PLE). UVB rays can also provoke allergies, but to a lesser degree.
UVB rays provide the energy your skin needs to make Vitamin D and stimulate the production of melanin which is responsible for tanning. They don’t travel as deeply as UVA rays, penetrating only the outermost layers of skin, but they cause more immediate damage such as sunburn. UVB rays are directly absorbed by cellular DNA which can lead to skin diseases such as actinic keratosis and skin cancer.
Both types of UV can induce hyperpigmentation and may contribute to conditions such as sun spots (also known as age spots) and melasma.
What is high-energy visible light and why does my skin need to be protected from it?
The sunlight spectrum consists of UV, visible and infrared light. Visible sunlight can be detected by the human eye, while the others remain invisible. Part of this visible spectrum has a high energy level and is known as high-energy visible light. It is also referred to as HEVIS light, HEV Light, HEVL and sometimes ‘blue light’ or ‘blue violet light’
Like UVA rays, HEVIS light penetrates the deeper layers of skin (the dermis) and can generate free radicals. These free radicals are one of the main causes of photoaging (premature skin aging caused by the sun). They interfere with skin cells and break down the collagen and elastin that gives our skin its plump, youthful appearance. HEVIS light has also been linked to uneven skin pigmentation and melasma.
Many modern sunscreens offer effective protection against UVA and UVB rays, but we recommend that you look out for products that also defend against the negative effects of HEVIS light. These products will give your skin reliable protection from photoaging and, in the long run, can also help to combat the visible signs of skin aging.
My skin is acne-prone. Do I need special sun care?
Yes. Effective sun protection is essential for all skin types and it’s particularly important for acne-prone skin for a number of reasons:
1) To protect against hyperpigmentation: When skin tissue is injured − as is the case with blemishes and acne − an excessive amount of melanin (skin pigment) can accumulate in one area. This surplus melanin remains after the spot has healed leaving a pigmentation mark. These pigmentation marks are particularly susceptible to the sun and the right sun protection will help to prevent them from darkening and becoming more noticeable.
2) To prevent skin from drying out: Oily skin still needs moisture. Over exposure to the sun causes it to dry out and the sebaceous glands (which products the sebum that gives skin the oil it needs) go into overdrive. This excess sebum is one of the key stages in the development of blemishes. When skin dries out its external layers harden and this can get in the way of the natural skin-shedding process. Dead skin can build up, block pores and exacerbate acne.
It’s also important to be aware that some acne medication and skin peels can make skin more sensitive to the sun and more susceptible to sun-induced skin damage. Products which are clinically and dermatologically proven to be suitable for acne-prone skin, such as Eucerin Sun Body Oil Control Aerosol Spray SPF 30, will give it the protection it needs.
