Computation of average concentric contraction of visual fields.

§ 4.76a Computation of average concentric contraction of visual fields. Table III—Normal Visual Field Extent at 8 Principal Meridians Meridian Normal degrees Temporally 85 Down temporally 85 Down 65 Down nasally 50 Nasally 60 Up nasally 55 Up 45 Up temporally 55    Total 500 EC04NO91.005 Example of computation of concentric contraction under the schedule with abnormal findings taken from Figure 1. Loss Degrees Temporally 55 Down temporally 55 Down 45 Down nasally 30 Nasally 40 Up nasally 35 Up 25 Up temporally 35    Total loss 320 Remaining field 500° minus 320° = 180°. 180° ÷ 8 = 22 1/2 ° average concentric contraction. (Authority: 38 U.S.C. 1155) [43 FR 45352, Oct. 2, 1978, as amended at 73 FR 66549, Nov. 10, 2008]