Uzma Samadani, MD, PhD, chief of neurosurgery, and colleagues at NYU Langone Hospital in New York have published a study showing the usefulness of eye tracking technology in diagnosing TBI. They used two groups of test subjects drawn from 169 veterans, some with abnormal eye movements and others with normal ones. They had both groups watch a music video or TV show for 220 seconds, during which a device scanned their eyes and a computer measured the ratio between vertical and horizontal eye movements. Patients with normal eye movements had a 1:1 ratio while patients with abnormal eye movements had abnormal ratios. The team found that abnormal ratios correlated with swelling in the brain near the site where cranial nerves controlled eye movement. Surgery to decompress the swelling cured the abnormal eye movement.