A clinical method to evaluate the visual performance in children is perceptual-visual analysis, but there are few publications that talk about neurophysiological methods that consistently support the visual-perceptual performance.
One may want to try searching journal articles about the occipital lobe and primary visual cortex. Complementary articles about the visual association and somatosensory cortex are available on ProQuest, ERIC, and a seemingly unlimited list of databases. for example. Additionally, information about the corpus callosum will more than likely offer support for accurately measuring visual-perceptual performance. Finally, see Dr. Andrew Wrobel, SNHU as well as Dr. Lindsey Josvai, Argosy University for more definitive algorithms.
Dr. Wrobel presented the following article to a SNHU PSY 634-Neuropsychology course; among a host of others.
Future Directions in the Study of Social Relationships as
Regulators of the HPA Axis Across Development
Camelia E. Hostinar and Megan R. Gunnar
Although the aforementioned is not the immediate answer to one's needs; it is a starting point.