The study by Alexandra Hospital homed in on 46 patients with age-related macular degeneration (AMD), in which the centre of the retina called the macula - which enables the eye to see details - deteriorates, resulting in blurred vision and even blindness.

It found that patients who had higher levels of pigment in the macula, from having eaten foods with natural pigments, could see better than those with lower pigment levels.

On a 16-line eye chart, patients with higher pigment levels saw 12 lines on average; those with lower pigment levels saw an average of only seven.

The main researcher of the study, Dr Kumari Neelam, 37, said: 'The significance of this finding is that, for people with macular degeneration, their vision will be better if they have more pigmentation.'

Two yellow pigments found in the macula, known as lutein and zeaxanthin, have the job of filtering out damaging rays of light. If they are in short supply, the macula of the eye becomes more vulnerable to damage from ageing or severe myopia.

Their levels can be raised only through eating foods containing such yellow pigments, such as green leafy vegetables, maize, kiwi, grapes, oranges, pumpkins, and wolfberries.

Read the full story in Wednesday's edition of The Straits Times.