You are here
Vision loss in children whose eyesight may be 20/20 requires new diagnostic and teaching strategies
NEI-supported research lays foundation for rehabilitation of brain-based visual impairment
NEI-funded research is aimed at objectively evaluating what people living with low vision due to cerebral (cortical) visual impairment (CVI) can and cannot see, especially in situations where a significant intellectual disability interferes with the ability to communicate or read an eye chart.
Toward that end, with NEI funding, Glen Prusky, Ph.D., director of the Laboratory for Visual Disease and Therapy at Burke Neurological Institute, White Plains, New York, developed a system that tracks eye movement to gauge how well a child living with CVI can see.
His system is based on observation of a reflexive behavior: When our eyes track an object gliding across our field of vision, they move smoothly. Take the object away, and without anything to focus on, our eyes are unable to move smoothly. Building on that idea, Prusky’s system assesses how well a child sees by presenting him or her with a large visual stimulus drifting across a computer screen. An infrared eye tracker plots where the child is looking, and an algorithm determines whether the child’s eye movements are smooth, indicating their fixation on the stimulus. When the child smoothly tracks, they are incentivized to keep trying to focus by being rewarded with a favorite song. The stimulus becomes increasingly difficult to see in order to identify the limit of a child’s functional vision.
“It’s really remarkable to see a child lying in bed not looking at much or tracking. And then you put this screen in front of them and you move stuff and almost like a light bulb you see them become engaged,” Prusky said.
