Scientists have developed innovative contact lenses that stimulate the brain and exhibit the same efficacy in treating depression in mice as the popular antidepressant Prozac. The soft, transparent lenses are equipped with embedded electrodes that deliver weak electrical signals to the brain through the retina, activating specific regions associated with depression. According to a study published in the journal Cell Reports Physical Science, after three weeks of therapy, behavioral, neuronal, and physiological symptoms were sharply reduced in mice with depression.
The study’s authors explain that since the eye is anatomically a part of the brain, the idea emerged whether a simple contact lens could become a non-invasive gateway to the brain circuits that regulate mood. According to them, this approach opens up an entirely new perspective for treating conditions such as depression, anxiety, cognitive decline, and even drug addiction.
The lens utilizes a method called “temporal interference.” Two safe electrical signals are delivered simultaneously to the retina, activating only at their point of intersection, which makes the treatment extremely precise. The authors compare this process to the crossing of two flashlight beams: each beam is weak on its own, but where they intersect, a bright spot appears. The lens electrodes are made of ultra-thin, transparent layers of gallium oxide and platinum.
To test its efficacy, the scientists compared four groups of mice: healthy mice, untreated depressed mice, mice treated with the antidepressant fluoxetine (the active ingredient in Prozac), and those undergoing lens stimulation for 30 minutes a day. After three weeks, the lens-treated group showed a restored connectivity between the hippocampus and the prefrontal cortex, which had been disrupted due to depression. Furthermore, blood levels of the stress biomarker corticosterone decreased by 48%, levels of the happiness hormone serotonin increased by 47%, and the number of inflammatory molecules in the brain declined.
Interestingly, when the obtained data was analyzed by an artificial intelligence model, it automatically classified the lens-treated mice into the healthy mice group rather than the depressed one, based on their behavior and biological indicators. The technology has yet to undergo rigorous clinical trials. In the next phase, the scientists plan to make the lens completely wireless, test its long-term safety on larger animals, and only then proceed to clinical trials on humans.
