Value of Two Horizontal Prisms held Over Either Eye
Prisms are assumed to be in the same direction (e.g. both base in or base out)
Actual Value in Prism Diopter with two horizontal prisms
PD | 20 | 25 | 30 | 35 | 40 | 45 | 50 |
20 | 42 | 47 | 53 | 59 | 65 | 71 | 78 |
25 | 47 | 53 | 59 | 66 | 72 | 79 | 86 |
30 | 53 | 59 | 66 | 73 | 80 | 87 | 94 |
35 | 59 | 66 | 73 | 80 | 87 | 95 | 103 |
40 | 65 | 72 | 80 | 87 | 95 | 104 | 113 |
45 | 71 | 79 | 87 | 95 | 104 | 113 | 123 |
50 | 78 | 86 | 94 | 103 | 113 | 123 | 133 |