What is "campimeter"

n. A device used to measure a person's field of vision

The campimeter is an instrument for examining the visual field. Campimeters have been in clinical use since the mid-nineteenth century. Initially, examination of the visual field was concerned only with the outer limits, or 'perimeter' of the visual field, hence the term ' perimetry', which tends to be used inter-changeably with 'campimetry'.