EXPERTS have launched a campaign to open people's eyes to the dangers of ultraviolet ray damage to their sight. While most people are aware that the sun can cause skin cancer, very few know that it can also harm your eyes.

Rosie Gavzey, director of the Eyecare Trust charity, says: "Excessive exposure to the sun's rays can lead to a sunburn-like condition called photokeratisis. This can be extremely painful and make your eyes red, swollen and watery."

Unprotected exposure to the sun over a long period of time greatly increases your risk of developing cataracts and other age-related conditions which can seriously impair vision, she adds.

This is even more important for children because more light reaches their retinas. "Ideally all children - and adults - should wear good quality sunglasses and a peaked hat when spending time outdoors, especially when children are playing on the beach or by water where there is a lot of reflected light," says Ms Gavzey.

The Eyecare Trust urges holidaymakers heading for the sun this summer to look out for the CE or BS EN 1836:1997 marks when choosing sunglasses to ensure they offer a safe level of ultraviolet (UV) protection.

Sunglasses are also marked with a filter category number from zero to four, where four is the darkest lens. Category four is suitable for exceptionally sunny conditions such as skiing, while category two or three should be fine for most occasions. A guide is available at www.eyecare-trust.org.uk