Don’t smoke, keep fit, eat a healthy diet rich in fish oils, low in fats and high in antioxidants are all ways to slow the degeneration of the macula, the eye’s most critical region for clear vision, says Professor Jan Provis of the ARC Centre of Excellence in Vision Science (The Vision Centre) and The Australian National University.

“Thanks to the macula humans have remarkably acute vision. It’s the little spot on the inside back of the eyeball that does most of our useful seeing, such as reading, recognising faces and spatial resolution. It’s usually fine for the first 50 years of life but then it starts to degrade and this leads to partial and sometime total loss of sight,” she explains.

Age-related Macular Degeneration (AMD), Bests' Disease, Stargardts' Disease and Macular Telangiectstasis are just some of the conditions which can have devastating consequences for people still otherwise active.

“Our research indicates that this is due to an evolutionary trade-off which has occurred in humans and other primates over time. We have developed extremely acute vision, partly because the number of blood vessels in the macula – and its central region, the fovea - is quite low. Having too many blood vessels would obscure our vision, so we have settled for a compromise: sharp vision in youth - but an unstable macula that deteriorates over time.

“Our eyes consist of very large numbers of neurons which combine to enable us to see well, and these demand quite large amounts of oxygen. However having fewer blood vessels the neurons in the macula can easily be starved of oxygen causing them to die in large numbers and this contributes to the typical decline in vision from mid-life onwards that most of us experience.”

While there is little that can be done at the present state of knowledge to reverse this degeneration, the good news is that there are things we can all do to slow or prevent it, she says.