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Over-refraction Calculator
Over-refraction Calculator
Enter the current prescription and the over-refraction finding. The calculator merges both prescriptions and displays the final result in both Plus (+) and Minus (−) cylinder formats.
Accepts both ± Sphere and ± Cylinder inputs
Displays clinical standard (0.25 D) & exact results Current Glasses Rx
D
D
°
Over-Refraction
D
D
°
+
Matches Input
Plus Cylinder Form (+cyl)
Clinical Result (0.25 D) —
Sphere — D
Cylinder — D
Axis — °
Exact Result (Unrounded)
Sphere —
Cylinder —
Axis —
Power @ Axis (0°): —
Power @ Axis+90° (90°): —
−
Matches Input
Minus Cylinder Form (−cyl)
Clinical Result (0.25 D) —
Sphere — D
Cylinder — D
Axis — °
Exact Result (Unrounded)
Sphere —
Cylinder —
Axis —
Power @ Axis (0°): —
Power @ Axis+90° (90°): —
Thibos Vector Components
Exact linear vector summation| Prescription | M (Spherical Eq) | J₀ (0°/90°) | J₄₅ (45°/135°) |
|---|---|---|---|
| Current Rx (v₁) | — | — | — |
| Over-Refraction (v₂) | — | — | — |
| Combined Net Vector (v₁ + v₂) | — | — | — |
* Plus cylinder axis and Minus cylinder axis are orthogonal (exactly 90° apart), producing identical net optical powers.