If the sun is hot enough to burn the skin, then it will also damage the eyes

Edmund McMahon-Turner Moorfields Eye Hospital

Charlotte Gann, editor of Health Which? said: "Check for the British Standard mark - as long as sunglasses have this they should provide enough protection from the sun, however little they cost.

"How much you want to pay for the most stylish shades is then up to you."

Experts also warned that the darkness of sunglasses is no indication of the protection they offer.

UV rays from the sun can damage the eyes, and the effect can build up over time.

Recent research has shown that exposure to sunlight may increase the risk of developing cataracts - the leading cause of blindness world-wide.

A cataract is a cloudy or opaque area in the normally transparent lens of the eye.

Edmund McMahon-Turner, of Moorfields Eye Hospital, said: "If the sun is hot enough to burn the skin, then it will also damage the eyes.

"People should also wear sunglasses in bright conditions, especially when skiing or holidaying near water - reflected light from these surfaces can increase the amount of UV light immensely."