UK researchers have developed a technique which could lead to an eye examination to find Alzheimer’s and other illnesses before symptoms manifest.

The scientists, from University College London, have developed ‘fluorescent markers’ which join on to dying cells, and which can be observed within the retina and show that brain cells are dying.

The researchers have already performed tests on mice but plan to carry out tests on human subjects later this year.

The technique could allow scientists to find out what is occurring in the brains of people with dementia. At present they must use MRI scans or carry out exams after death has occurred.

Professor Francesca Coredeiro, lead author from University College London Institute of Ophthalmology said: “Few people realise that the retina is a direct, albeit thin, extension of the brain. It is entirely possible that in the future a visit to a high-street optician to check on your eyesight will also be a check on the state of your brain.”

“I hope that screening for Alzheimer’s will be available on the high street within five years.”

Rebecca Wood, Chief Executive of the Alzheimer’s Research Trust, said the research could potentially “transform” methods of diagnosing dementia and could hugely enhance the search for new treatments.

She added that 700,000 people in the UK had Alzheimer’s and other types of dementia, and that figure was expected to “double within a generation” if scientists did not make fast developments in their efforts to find a cure.