Eat corn, spinach, orange peppers and eggs - and don't smoke - if you want to avoid age-related macular degeneration, one of the world's most common forms of seriously impaired vision. It's also best not to be a woman with blue eyes and fair skin who has a parent with the condition - but these are outside your control, of course.
The condition affects one in five Irish people over the age of 70 and one in three over 85. Because people are living longer, it is becoming more common and therefore more costly for health services.
As the population continues to age, the condition will become an even more important issue, particularly as each treatable case - and only about one in 10 cases cannot be treated - costs at least £4,000 to cure.
Sufferers of age-related macular degeneration, of which there are about 30 million worldwide, lose some of their central vision. They therefore cannot watch television, read normal print, knit or sew. Although they do not need guide dogs or white sticks, as they retain peripheral, or navigational, vision, they are classified as blind.
Sufferers complain of seeing their grandchildren in their side vision, then not being able to focus on their faces. So they sense their grandchildren's presence without being able to see their faces change as they grow up.
So if you're planning on staying around a while, plan for preventing age-related macular degeneration. One essential step is to visit your optometrist for an eye test once every two years, whether or not you wear glasses, after the age of 40. This message is being spread by the Association of Optometrists Ireland as part of National Eye Week.
Two forms of age-related macular degeneration have been identified: the "dry" form and the more severe "wet" form. Dry age-related macular degeneration - the more common and milder form of the condition - accounts for about 90 per cent of all cases, and results in varying forms of sight loss. The chance for severe sight loss is much greater from the wet form. While more rare, wet age-related macular degeneration leaves 70 per cent of its sufferers legally blind within two years.
The most fascinating discovery about the condition is that lutein, a pigment found in spinach, eggs and other foods, is essential to the health of the macula, which is the centre of the retina and normally provides our sharpest vision.
Genetics are also important, as dark-eyed people tend to avoid the condition. Dark eyes absorb only 1 per cent of the light absorbed by blue eyes, and the macula is the part of the eye that deals with "blue" light. So another important preventive measure, especially if you have blue eyes, is to wear good sunglasses. It's not the cost that matters, but the power of the lenses to filter out light.
Pharmaceutical companies are promoting lutein supplements as a way of avoiding age-related macular degeneration. But taking supplements is not a method endorsed by Stephen Beattie, who works with Pat Hayes and Peter Tormey in the ophthalmology unit of Waterford Regional Hospital, which is at the forefront of treating the condition.
Beattie, who recently returned to the Republic from the UK, emphasises the "whole diet" as important in preventing it. It could be that lutein is more effective when combined with vitamins C and E, in which case it wouldn't be enough to take lutein tablets alone.
In ground-breaking research, Beattie proved that age-related macular degeneration is directly linked to the lack of macular pigmentation that follows low lutein levels.
A lack of lutein is partly related to diet, partly related to having blue eyes and partly related to smoking. Like so many conditions, age-related macular degeneration is caused by a complexity of lifestyle and genetic issues.
What's interesting is that people in India and Japan don't get the condition if they live traditionally, but they do if they westernise their diets. So while genetics are important, diet and smoking are also significant factors.
The severe, wet form of the condition is caused by blood leaking from the vessels under the retina. A proportion of sufferers can benefit from "cold" laser treatment, or photodynamic therapy, which destroys blood vessels without damaging the overlying retina. (The dry form is caused by deterioration and a build-up of dead cells; there is no bleeding, and laser treatment is ineffective.)
About four treatments are required, three months apart, at a cost of £1,000 each.
"It's not a wonder cure - it does not restore vision - but does delay a drop in vision. And I do think the Government should pay for it," says Beattie.
Some health boards have initiated programmes to pay for treatment. VHI is looking for "further evidence to confirm its safety" before covering photodynamic therapy.
A UK committee classified the treatment as in category B for efficacy; VHI covers only category-A treatments. BUPA says it has not been approached for photodynamic-therapy cover, but that it would cover the procedure were its efficacy proven.
Whether the public health service should cover the treatment has caused controversy in Northern Ireland. "Some have questioned whether a procedure which costs so much should be covered if it is not 100 per cent successful," says Mary Eustace, the president of the Association of Optometrists Ireland.
An eventual cure for age-related macular degeneration, in both its forms, may eventually come through gene therapy. Dr Paul Kenna of Trinity College, Dublin, who discovered the gene for retinitis pigmentosa, a form of blindness that affects one in 3,000 Irish people, says that the treatment of blindness is an area that could benefit from stem-cell research.
The best prevention, he says, is to choose your parents - which we cannot do, of course - and eat lots of leafy green vegetables all your life. At 60, it's too late to start. If you're 40 or older, you need to be aware that your eyes are at greater risk of numerous conditions in addition to age-related macular degeneration.
During National Eye Week, the Association of Optometrists Ireland is offering a free leaflet that contains basic information and advice on eye conditions such as "spots and floaters", dry eye and cataracts, as well as covering the major eye diseases that people become more susceptible to as they age, which include glaucoma and diabetic retinopathy.
Glaucoma accounts for 10 per cent of blindness, yet you may not realise you have it until it is too late, as it is symptomless and painless in its early stages. The disease is treatable if detected in time, however. Those at greatest risk include black-skinned people over the age of 40, everyone over the age of 50 and people with family histories of glaucoma.
One in 20 people have diabetes, and 90 per cent of these will develop diabetic eye problems. Diabetic eye disease is the most common cause of blindness in working people aged 25 to 65, and sufferers may be unaware that they are developing complications until the damage is well advanced.
The message the Association of Optometrists Ireland would like to get across is that half an hour could save your sight, which is why it is encouraging people to have two-yearly eye examinations.
It is also offering a complimentary self-screening kit during National Eye Week to those over 40. Available from opticians around the Republic, the kit includes charts that can screen for symptoms of eye disease.
Anybody who suspects they have identified an eye problem by using the kit should consult their optician, who can then offer them advice and a full eye examination.
For more information, e-mail the Association of Optometrists Ireland at aoi@eircom.net