Before revision: 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
After revision: '.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