The huge boom in popularity followed media reports that hailed these tiny berries as being capable of helping to protect the body against a wide range of ailments, including cancer, heart disease and dementia.

But the idea that blueberries might protect your eyes is not a recent one. During the second world war, bilberries (a form of blueberries that grow in the wild) were eaten by British pilots to improve their night vision. Since then, research has suggested that blueberries benefit eyesight, eye fatigue and night blindness.

Blueberries contain anti-oxidant compounds called anthocyanins, which are responsible for giving the fruits their blue hue.

Antioxidants are thought to increase the retinal pigments (colouring agents) that allow the eyes to tolerate light. These compounds may help to make the walls of blood vessels in the eyes stronger by increasing the number of collagen linkages.

Collagen supports and maintains bodily structures, such as skin and bones.

By strengthening the capillaries, anthocyanins help to increase blood flow in and around the eyes. These effects may be responsible for the many claims about improved vision and eye health.

They may also be the reason why bilberry and blueberry supplements are flying off the shelves.

But while there haven't been any reports of major side-effects from taking bilberry supplements, there haven't been any clinical trials on humans confirming the health benefits of bilberry or blueberries.

Bilberries contain compounds called tannins. High levels of tannins - found in these health supplements - have been linked to kidney and liver damage, as well as lip and tongue cancer.

The key to optimal health - including eye health - is a balanced diet which includes a healthy mix of different foods.

Just because something has been labelled a superfood doesn't mean it can replace all other foods. A mixture of nutrients from different foods - including superfoods - is the best protection against diseases of all kinds.

Larissa's diary

Breakfast: Bread with different toppings; milk

Lunch: Cafeteria food eg. pizza or garlic bread; water or chocolate milk

Dinner: Rice with chicken, sushi; water

Snacks: Chips, cookies, string cheese; milk and apple juice

Exercise : Football training every week