A trip to your eye doctor will now detect whether you have Alzheimer’s disease or not. A technique developed by British researchers highlights damage done to nerve cell in the eye’s retina which associates to nerve cell damage in the brain.

Researchers said that the cheap test in which eye-drops are applied before taking a photo using an infrared camera could detect dementia. Treatment can be started after the diagnosis.

Professor Francesca Cordeiro, who worked with Professor Stephen Moss, lead author at University College London, said, "Few people realise that the retina is a direct, albeit thin, extension of the brain. The death of nerve cells is the key event in all neuro-degenerative disorders – but until now it has not been possible to study cell death in a living eye.”

The technique, which would start trials on humans later this year highlights damage in the nerve cells using a chemical marker that glows when damage is found.

Alzheimer's charities welcoming the research said this technique could change the way the disease was diagnosed and monitored earlier and raises a new hope.

Dementia’s most common form is Alzheimer's and it affects in U. K. alone about 700,000 people. In the next decade, about one million Britons are expected to develop dementia.