CONSUMING ORANGES OR ORANGE JUICE ON A DAILY BASIS COULD CONTRIBUTE TO PREVENTING AGE RELATED MACULAR DEGENERATION: CLAIMS SUPPORTED BY AUSTRALIAN RESEARCHERS
That fruit and vegetables help protect our retina, especially the macula, has long been known. However it appears that, above all, oranges may be particularly useful in preventing age-related macular degeneration (AMD), although this is yet to be fully understood. A team of Australian university researchers are carrying out research to this effect, and state that, “drinks that contain flavonoids (such as orange juice) are reasonable to be recommended to patients.”
Reference is made to consuming at least one portion per day, equivalent to a large orange or 200-300ml of squeezed juice. On Original Research Communications the authors explain:
Flavonoids are bioactive compounds found in foods such as chocolate, tea, red wine, fruit and vegetables. […] They can have an antioxidant and anti-inflammatory action. There is also strong evidence that flavonoids positively affect vascular health through improved endothelial function. Therefore, their role seems promising in reversing oxidative stress and associated inflammatory damage, as well as improving vascular function and clinical signs of AMD.
Other studies have already been conducted to try to find ways to prevent age-related macular degeneration. The authors of the study summarize the results as follows:
Age-related macular degeneration (AMD) is the leading cause of blindness and major reduction of sight among ‘elderly adults.’ Current studies suggest that people affected by AMD should consume dark green leafy vegetables daily, follow low-glycemic diets and eat fish (at least twice per week). The study AREDS (Age-Related Eye Disease Study) showed that taking food supplements containing high doses of vitamin C, β.-carotene, zinc and copper could reduce AMD progression by 25%. 
The factors to be taken into account – also at a lifestyle level – are many: not only diet (it is also important to consume fish regularly), but also not to smoke and take daily physical exercise. Alongside these modifiable aspects there is one that cannot be changed: genetic predisposition. Anyone who has a first-degree relative affected by AMD has a 3-6 times higher chance of being affected by it. In any case, after the age of 60, it is advisable to undergo at least one eye examination per year.
Main sources: Original Research Communications, Westmead Institute For Medical Research
 However the magnitude of this result has been significantly reduced in a subsequent study