There may soon be a painless way for diabetics to monitor their blood sugar levels.

Researchers at the University of Akron are working on contact lenses that change colour when they detect a change in the sugar levels of the person wearing them.

Diabetic patients currently have to rely on painful ‘skin prick’ tests.

Blood is not the only way to measure glucose levels in one’s body, urine and tears are also reliable measures.

The researchers are working on a contact lens coated with a chemical that reacts to glucose in the tears that naturally surround the eye. If sugar is not being metabolized properly and glucose concentration builds up in the body, the contact lens will detect a problem and change colour.

Lead researcher Jun Husays says “it works just like P.H. paper in your high school chemistry lab.’

The colour changing lenses could find themselves in the market in as few as three years.