The device, 16mm long, 3-4mm wide and 1-2mm thick, was implanted beneath the inferior lacrimal gland in rabbit eyes. It was activated wirelessly, and shown to increasing the generation of tears by nearly 57 percent.

'Dry eye' - deficiency of the tear film on the surface of the cornea leading to inflammation of the cornea and conjunctiva - is one of the most common eye disease, affecting 5-6 percent of the population. Currently it does not have an effective treatment.

The researchers also discovered that the afferent neural pathway - the neural pathway from sensory neurons to the brain which activates the reflex tearing - offered an even more efficient way to enhance tear production.

The next phase of the research will be to evaluate the 'quality' of the tears produced, as in addition to volume, protein and lipid content are important. The device is currently undertaking clinical trials.

The study was published in the Journal of Neural Engineering.