Direct sunlight on the naked eye can result in a progressive eye disease called age-related macular degeneration (AMD), the most common cause of blindness in the western world, according to Dr Stephen Beatty, consultant ophthalmologist from the Macular Pigment Research Group at Waterford Institute of Technology (WIT).

"It is not an exaggeration to say that we are currently in an epidemic of this condition, " he said. "It is estimated that there are 60,000 people in Ireland suffering from AMD, but that is a gross underestimation because many more people will have an early form of the disease and not realise it."

Beatty said that AMD is the "opposite of tunnel vision" and is extremely frustrating for sufferers. The condition occurs when the macula . . . the centre of the retina . . .

degenerates, leaving a person unable to see what is directly in front of them. It affects people over 55.

"Sufferers will retain their peripheral vision, but they can't see what they are actually looking at, " said Beatty. "They can't read, drive, recognise faces or watch television. In effect, they lose their independence. And now, because people are living longer, more and more people are vulnerable to this condition."

It has traditionally been recognised that age, smoking and family history were the three main causes of AMD. However, there is a growing body of evidence which proves that cumulative exposure to sunlight over a person's lifetime is also a factor in the disease, said Beatty.

"People are vulnerable to the sun all year round, so it is important to protect the eyes when possible with sunglasses or a hat, " he said. "We are also investigating whether dietary supplements containing lutein, for example 'Ocuvite Lutein', could delay onset of the disease. Lutein makes up the macular pigment in the eye which filters out damaging sunlight. It is found in high quantities in leafy green vegetables."