Diabetes is a condition that afflicts hundreds of millions of people around the world.  Visual impairment is a considerable risk for these people, and whilst treatments do exist, they are very painful and invasive.

A team from Caltech have developed a glow-in-the-dark contact lens that they hope will provide a much less frightening and invasive form of treatment.

Loss of vision

The loss of vision suffered by diabetes patients is down to the damage caused to tiny blood vessels by the disease.  When this damage occurs in the eye, it results in reduced blood flow to the retina, and their eventual death.  Whilst the body attempts to counter this by growing new blood vessels in the eye, these attempts tend to fail in diabetic people, resulting in first blurry vision before it fades away completely.

The damage begins with an insufficient supply of oxygen to the retina, so the team hoped to devise a method for reducing the oxygen demands in the eye that don’t require laser surgery or injections into the eyeball.  Their lenses reduce the metabolic demands of the retina, especially at night when they’ve believed to require much more oxygen.  They do this by giving the rod cells in the eye a small amount of light to look at whilst the wearer sleeps.

The team borrowed technology from wristwatches that contain glowing markers on their faces.  The technology provides a constant light output for the lifetime of the contact lens.  The light sources are designed to be outside the wearer’s view when the pupils are constricted in lighted conditions, but as the pupil expands in darkened conditions, the faint glow illuminates the retina.

Suffice to say, this kind of ‘light therapy’ has been attempted before via devices such as lighted sleep masks, but the results haven’t been particularly good.  The team are confident that their contact lenses will do a much better job.

In early testing of the device, it reduced rod cell activity by up to 90% when worn in the dark.  The team plan on testing whether this will translate into the prevention of diabetic retinopathy.  If this goes well, the team will seek FDA permits to begin clinical trials.

Suffice to say, the device is some way from being commercially available, but it’s a nice example of how a devastating problem could be tackled in an innovative way.