38 C.F.R. § 4.76a Computation of average concentric contraction of visual fields.
Title 38 - Pensions, Bonuses, and Veterans' Relief
The extent of contraction of visual field in each eye is determined by recording the extent of the remaining visual fields in each of the eight 45 degree principal meridians. The number of degrees lost is determined at each meridian by subtracting the remaining degrees from the normal visual fields given in table III. The degrees lost are then added together to determine total degrees lost. This is subtracted from 500. The difference represents the total remaining degrees of visual field. The difference divided by eight represents the average contraction for rating purposes. Example of computation of concentric contraction under the schedule with abnormal findings taken from Figure 1. [43 FR 45352, Oct. 2, 1978]
Title 38: Pensions, Bonuses, and Veterans' Relief
PART 4—SCHEDULE FOR RATING DISABILITIES
Subpart B—Disability Ratings
The Organs of Special Sense
§ 4.76a Computation of average concentric contraction of visual fields.
Table III_Normal Visual Field Extent at 8 Principal Meridians------------------------------------------------------------------------ Normal Meridian degrees------------------------------------------------------------------------Temporally.................................................. 85Down temporally............................................. 85Down........................................................ 65Down nasally................................................ 50Nasally..................................................... 60Up nasally.................................................. 55Up.......................................................... 45Up temporally............................................... 55 ----------- Total...................................................... 500------------------------------------------------------------------------
------------------------------------------------------------------------ Loss Degrees------------------------------------------------------------------------Temporally.................................................. 55Down temporally............................................. 55Down........................................................ 45Down nasally................................................ 30Nasally..................................................... 40Up nasally.................................................. 35Up.......................................................... 25Up temporally............................................... 35 ----------- Total loss................................................. 320------------------------------------------------------------------------Remaining field 500° minus 320° = 180°. 180° ÷ 8 = 22\1/2\° average concentric contraction.
