Measurement of the visual field will be made when there is disease of the optic nerve or when otherwise indicated. The usual perimetric methods will be employed, using a standard perimeter and 3 mm. white test object. At least 16 meridians 221/2 degrees apart will be charted for each eye. (See Figure 1. For the 8 principal meridians, see table III.) The charts will be made a part of the report of examination. Not less than 2 recordings, and when possible, 3 will be made. The minimum limit for this function is established as a concentric central contraction of the visual field to 5°. This type of contraction of the visual field reduces the visual efficiency to zero. Where available the examination for form field should be supplemented, when indicated, by the use of tangent screen or campimeter. This last test is especially valuable in detection of scotoma.