By the time most kids are diagnosed with autism, they're somewhere between the ages of three and five years old. Now, new research points towards a potential means of diagnosing children much, much sooner — and it all comes down to eye contact.

In a study funded by the National Institutes of Mental Health and published in Nature, researchers followed 110 children from infancy to three years of age. Half of those children were at a high risk of developing autism (because they had siblings with the condition) while the other half weren't. Using eye-tracking technology, the team routinely evaluated how often the babies looked into the eyes of a caretaker on video, and how long they held the gaze. When the children were three, and underwent autism screenings, researchers found that those whose eye engagement lagged during infancy were more likely to be diagnosed with the condition.

Increasingly diminished eye contact over weeks and months

More specifically, infants who were later diagnosed with autism exhibited a drop in eye contact when they were between two and six months old. These infants also exhibited increasingly diminished eye contact over weeks and months, whereas their non-autistic peers engaged to a greater extent over time. "Kids whose eye fixation falls off most rapidly are the ones who later on are the most socially disabled and show the most symptoms," study author Warren Jones, director of research at the Marcus Autism Center, told the New York Times. "Our ultimate goal is to translate this discovery into a tool for early identification."

Can't yet be replicated at home

Though the study was small, the same team is now conducting more research on a larger group of children. They also caution that the sorts of ultra-subtle eye moments tracked in this research can't yet be replicated at home and without equipment. But if these findings are further validated, they could point towards earlier diagnosis and maybe even more effective interventions for at least certain infants.