Hi-tech images of the retina could allow earlier diagnosis of eye diseases, researchers suggest.
The retina of a patient with diabetic retinopathy
The spectral imaging technique enables doctors to spot changes in blood vessels in the eye.
The Heriot Watt University researchers who developed it said it could help detect glaucoma, diabetic retinopathy and age-related macular degeneration.
Details of the imaging technique were presented to the Institute of Physics conference in Glasgow.
It is estimated that by 2020, there will be 200m visually impaired people in the world, but 80% could be prevented or treated.
The spectral imaging technique uses a standard ophthalmoscope which has been adapted so it can take a series of images of the retina at specific wavelengths.
It shows how oxygenated the blood flowing out of the retina is. The higher the oxygenation level, the less healthy the retina.
Spotting this early allows doctors to then look at what could be causing the problem.
The images are captured by a sophisticated digital camera. Image processing corrects for the movements of the eye while the pictures are being taken, and a large set of images are combined to provide the clearest depiction possible.
Dr Andrew Harvey, who helped develop the technique, told BBC News Online: "This new technique is safe, quick and simple, and totally non-invasive so going for regular check-ups every four months won't be so daunting for patients."
He said some existing methods of checking the eye could be painful for patients, or even cause side effects, potentially deterring them from having eye examinations as often as they should.
Dr Harvey added: "So far, we've used this technique to take images of the retina in healthy subjects, patients with diabetic retinopathy and patients with glaucoma and in all cases it seems that our images are extremely successful in helping doctors detect and chart the condition.
An image of a healthy retina
"We're now at the stage of trialling this much more rigorously in a clinical setting but are very hopeful that this will be a promising new tool that will help doctors screen and monitor the major diseases of the eye."
Natasha Ede, a care advisor for Diabetes UK, said: "This technique is still going through clinical trials but we'll be following it's progress closely.
"Anything which can safely help to identify diabetic retinopathy at an early stage is to be welcomed.
"Retinopathy is the leading cause of blindness in adults of working age. However, good blood glucose and blood pressure control along with early detection through regular eye checks can reduce your risk of developing the condition."