We developed a device, Pediatric Perimeter, that quantifies visual field extent (VFE) for infants. Pediatric Perimeter is a hemispherical dome with light emitting diodes (LEDs). The LEDs are controlled using a computer program to measure Reaction Time (RT) to Gross Visual Fields (GVF) and the VFE. Infants lie down in the dome positioned in a dark room. Eye or head movement towards the stimuli is monitored with an infrared (IR) camera.