Sun sense

Once considered a sign of healthy living, bronzed skin is now widely seen as an indication of unwanted things to come: dullness, wrinkles, age spots and skin cancer.

Dr Goh Boon Kee, consultant dermatologist at Skin Physicians in Singapore, notes that sun exposure can cause up to 90 per cent of visible ageing as a result of the degradation of collagen and elastin. "The sun can cause accelerated ageing, resulting in wrinkles, colour changes and loss of elasticity," he says.

In order to prevent skin from going 50 shades darker and the potential health - and beauty - risks that come with it, the skincare industry offers an ever-increasing variety of sun protection products from traditional creams and mineral powders to tinted moisturisers.

The basis of any sunscreen discussion begins with ultraviolet (UV) rays. Divided into UVA, UVB and UVC, each type penetrates the skin differently. UVC is largely blocked by the ozone layer and is negligible in its harm to the skin. UVA, which has a longer wavelength, is the source of 95 per cent of all UV radiation. Besides penetrating surfaces such as glass, UVA rays penetrate deep into the skin and generate damage-inducing free radicals. UVB rays are the chief cause of redness in the skin and can directly affect the cells, harming DNA. They are also the primary cause of skin cancer.