Materials scientists have designed brain-stimulating contact lenses that are\u00a0as effective as Prozac at treating depression in mice.\u00a0The soft, transparent contact lenses have in-built electrodes that deliver mild electrical signals to the\u00a0brain via the retina\u00a0to stimulate specific brain regions associated with depression.<\/p>\n
Publishing\u00a0May 14th, 2026, in the Cell Press journal\u00a0Cell Reports Physical Science,\u00a0the paper shows that\u00a0depressed mice\u00a0displayed\u00a0reduced\u00a0behavioral, neural, and physiological\u00a0signs of depression after three weeks of\u00a0treatment with\u00a0the contact\u00a0lenses.<\/p>\n
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Our work opens up an entirely new frontier of treating brain disorders through the eye. We believe this wearable, drug-free approach holds tremendous promise for transforming how depression and other brain conditions\u00a0are treated,\u00a0including anxiety, drug addiction, and cognitive decline.”<\/p>\n
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Jang-Ung Park, Study Senior Author and Materials Scientist, Yonsei University<\/p>\n
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Current depression treatments, including drugs, electroconvulsive therapy, and brain implants, work by targeting brain regions and circuits that are associated with mood. Since the retina connects to some of these regions,\u00a0the researchers wanted to\u00a0try\u00a0using\u00a0the eye as a\u00a0pathway to\u00a0stimulate the\u00a0brain.<\/p>\n
Previously designed smart contact lenses have been used to\u00a0monitor\u00a0eye and metabolic disorders, for example,\u00a0by measuring eye pressure or glucose levels, but this is the first time contact lenses have been used to treat\u00a0a brain\u00a0disorder.<\/p>\n
“Because the eye is anatomically a part of the brain, we wondered whether a simple contact lens could serve as a gentle, non-invasive doorway to brain circuits that control mood,” says Park.<\/p>\n
The contact lenses stimulate the brain using a method called\u00a0temporal interference, which delivers\u00a0two electrical signals to the retina. These electrical signals only\u00a0become active at their point of intersection,\u00a0which\u00a0means that the treatment is very precise in only targeting specific brain regions.<\/p>\n
“Think of two flashlights: each beam alone is dim, but where they\u00a0overlap,\u00a0a bright spot appears, and that bright spot can be created far away from the flashlights themselves. Our contact lens does the same with two harmless electrical signals,” said Park.\u00a0“Even though the electrodes sit on the surface of the eye, the signals only become active where they meet at the retina deep inside the eye, gently activating\u00a0the\u00a0natural wiring that carries the signal to mood-related brain regions.”<\/p>\n
The researchers designed the lenses to be flexible and transparent\u00a0by\u00a0building electrodes from\u00a0ultrathin\u00a0layers of\u00a0gallium oxide and platinum\u00a0and then\u00a0tested the contact-lens-delivered temporal interference in mice\u00a0with\u00a0induced depression.<\/p>\n
They\u00a0compared four groups of mice: non-depressed control mice, depressed mice who did not receive any treatment, depressed mice who received\u00a0temporal interference, and depressed mice who received\u00a0fluoxetine, a selective serotonin reuptake inhibitor (SSRI) and the active ingredient in Prozac.\u00a0To assess the mice’s depression\u00a0before and after\u00a0treatment, the team used behavioral assays, electrophysiological brain recordings, and\u00a0measured blood and brain\u00a0biomarkers\u00a0associated with\u00a0depression.<\/p>\n
The contact lens treatment reduced signs of depression in all three categories.\u00a0Mice that received\u00a0temporal interference stimulation\u00a0for 30 minutes per day for three weeks\u00a0showed behavioral improvements that were comparable with mice who received\u00a0fluoxetine.\u00a0Recordings of brain activity revealed\u00a0that the treatment\u00a0restored\u00a0connectivity between the hippocampus and prefrontal cortex\u00a0that was lost due to depression.<\/p>\n
The treatment also\u00a0partially restored\u00a0the\u00a0levels of biomarkers associated with depression, including\u00a0reduced levels of inflammatory molecules in the brain,\u00a0a 48 % reduction in blood\u00a0corticosterone,\u00a0and\u00a0a 47 % increase in serotonin levels\u00a0compared to the untreated depressed mice.<\/p>\n
“We were struck that improvements appeared together across behavior, brain activity, and biology\u00a0and that the effect was comparable to a widely used antidepressant drug,” says Park.<\/p>\n
When the researchers asked a machine learning model\u00a0to group the mice based on their behavior, brain activity, and biomarker<\/a> levels, the model\u00a0consistently grouped\u00a0mice in the contact lens\u00a0treatment group with\u00a0non-depressed control mice\u00a0rather than with\u00a0mice in the\u00a0untreated depression\u00a0group.<\/p>\n “Like any new medical\u00a0technology,\u00a0our contact lenses\u00a0will need to go through rigorous clinical evaluation in patients before reaching the market,” says Park.\u00a0“Next, we plan to make the lens fully wireless, test it for long-term safety in larger animals, and personalize the stimulation for each user before advancing into clinical trials in patients.”<\/p>\n Source:<\/p>\n Journal reference:<\/p>\n