Now, a new technique to detect onset of blindness

Using standard clinical techniques, the detection of AMD has previously not been possible in the disease`s early stages. Doctors tend to diagnose AMD once small changes become visible at the back of a patient`s eye. However, degeneration begins many years before these clinical signs appear.

Now, a team at Queensland University of Technology, led by eye specialist Dr Beatrix Feigl, has come up with the "dim light vision" test which it says is very sensitive to early changes in a person`s vision.

"We can detect subclinical visual impairment in healthy participants genetically at risk for AMD. In the future we hope this test might be utilised by ophthalmologists and optometrists to identify patients with a high genetic risk of developing AMD but without any clinical signs of disease.

"This would enable specialists to advise patients on lifestyle changes which may delay disease onset and reduce its severity," she said.

Dr Feigl said that genetic pre-disposition accounted for around half the cases of AMD. However, lifestyle risk factors for AMD, which could be controlled by a patient, included poor diet, lack of exercise and smoking.

"We know that lifestyle changes can decrease a person`s chance of getting worse forms of the disease," she said.