Waterloo researchers find potential cure for adults with lazy eye

Researchers at the University of Waterloo working in collaboration with China's Sun Yat-sen University say they've found the first potential treatment for adults with lazy eye.

Condition previously thought to be untreatable in fully-developed brains

University of Waterloo assistant professor Ben Thompson, right, says research shows that adult brains do have the capacity to change through electrical stimulation. (University of Waterloo/Martin Schwalbe)

Researchers at the University of Waterloo working in collaboration with China's Sun Yat-sen University say they've found the first potential treatment for adults with lazy eye. 

In a news release, the Canadian university said research done with their Chinese counterparts has shown "low voltage electric currents can temporarily improve sight in adult patients with lazy eye, or amblyopia."

Until fairly recently, the prevailing view was that if adults couldn't develop amblyopia, they couldn't be treated for it.- Ben Thompson, UW professor

According to the WebMD website, the condition is associated with children who don't experience the normal development of vision and often plagues one eye.

If left untreated in youth, it was previously thought that the vision impairment would become permanent. 

Ben Thompson, an assistant professor at the University of Waterloo, said this potential treatment option is a new revelation for adults with the condition.

"Until fairly recently, the prevailing view was that if adults couldn't develop amblyopia, they couldn't be treated for it," said Thompson. "This was the same for anyone with brain-based vision problems — they're often told there's nothing that can be done about their vision loss."

Vision improved by currents

Patients had their primary visual cortex exposed to 20 minutes of transcranial direct current stimulation (tDCS) applied to the surface of their head. The brain stimulation exercise used constant, mild electrical currents in a painless way through electrodes. 

"They found the treatment temporarily increased the response of that part of the brain to visual information from the lazy eye," the release said, adding, "tDCS also improved patients' ability to see low contrast patterns."

The results were made public this month in Scientific Reports, an open access journal available online. 

"It's a long-held view that adults can't be treated for lazy eye because their brains no longer have the capacity to change," said Thompson. "We demonstrate here that adults do have the capacity, especially when it comes to vision."


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