Those registered as blind rose from 5,002 in 1996 to 6,862 in 2003, almost five times the rate of population growth.

While most cases of loss of vision result from the natural ageing process, there was a huge increase in the number who lost their sight due to diabetes.

The number of cases of diabetic retinopathy (DR) — a diabetes-related disease — rose by 120% from 147 to 323 people, including many from younger age groups. DR rose from the 11th most-common cause of sight-loss in 1996 to fifth in 2003.

Sight loss due to diabetes was the third most-common cause of new registrations overall in 2003 and the second most-common among working adults aged between 16 and 64.

“(DR) is the one we are very worried about,” said Colm O’Brien, an ophthalmologist at the Mater hospital and one of the authors of the study.

“It is treatable and preventable. DR visual impairment shouldn’t be happening in this day and age. It should be possible to identify the sight-threatening forms at a stage when treatment should bring about benefit.”

O’Brien said the problem was caused because there are now so many diabetics but there is not enough medical personnel or funding to identify everyone who requires treatment. A national screening programme is needed for early detection of the disease, he said.

About 200,000 people have diabetes in Ireland. The most common form, type-2, currently accounts for 85% of cases, with obesity and physical inactivity levels mostly to blame.

Anna Clarke, health promotion officer of the Diabetes Federation of Ireland, said: “You may have type-2 diabetes for up to 12 years and not know anything about it.

“The majority of people are currently being diagnosed with diabetes as a result of having vision problems or a heart attack. About half of the people diagnosed with type-2 diabetes have problems with their eyes.”

Elaine Howley, the director of services at the National Council for the Blind of Ireland, said: “I don’t think people are aware that vision impairment can be linked to diabetes and it is important for them to keep an eye on their diet and lifestyle. ”

Age-related macular degeneration (ARMD) remains the leading cause of loss of vision in Ireland. It increased by 113% over the study period, from 812 cases to 1,729.

Of the new cases of blindness registered in 2003, ARMD accounted for 44%, largely attributable to the country’s ageing population.

The numbers registered blind as a result of glaucoma remained relatively stable.

A substantial drop — 53% — was recorded in the number of people being declared blind due to cataracts. Formerly the third most-common cause of blindness, it is now eighth.

Over-65s made up 56% of those on the blind register. While there was a 5% increase in the pensioner population during the period, the numbers registered as blind jumped 36%.

“We can’t fully explain it by the increase in the number of aged people,” said O’Brien. “The problem is only going to increase as we have an older population which is living longer.”

The study, carried out by specialists at the Mater hospital in conjunction with the National Council for the Blind of Ireland, was published in the British Journal of Ophthalmology.

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