Researchers at Perkins School for the Blind are studying the brain scans of children with cerebral visual impairment (CVI), to compare with those of children with normal vision or other forms of ocular blindness, and have developed a digital assessment tool for educators to learn more about the disorder.
The primary cause of paediatric visual impairment and blindness in the US and developed countries, CVI is commonly caused brain injury, trauma, infection, seizure, or a genetic or metabolic disorder prenatally or during birth. Researchers at Perkins, where 52% of the population has CVI, investigated how the disorder differs from other eye-based visual impairment, devising a tool that uses eye tracking and virtual reality to assess CVI children as they tackle various tasks.
“We found that the children are very sensitive to clutter, crowding, complex motion and, more interestingly, to visual demands," explained Perkins CVI Steering Committee member Dr Lotfi Merabet, associate professor of ophthalmology at Harvard Medical School. "As the task becomes much more difficult, their visual system breaks down." A standard vision test might indicate these children have normal visual acuity, but when put into a situation where the visual system is taxed, the hidden visual impairment manifests itself. This prompted the development of the Perkins CVI Protocol, he said. “This digital tool offers more than just a functional vision assessment – it will create a series of reports to help parents, teachers of the visually impaired (TVIs), school systems and medical professionals understand and meet the unique needs of each individual child with CVI.”
