Description
Conventional index-minus-one over radius power using a caller-supplied keratometric index, not true two-surface corneal power.
Vision research uses stimulus angles, chart notations, image scales, viewing distances, coordinate origins, and observation windows. These quantities have different denominators and measurement conventions. A conversion or support share does not independently establish a visual measurement or its clinical interpretation.
Conventional index-minus-one over radius power using a caller-supplied keratometric index, not true two-surface corneal power.
When to use this tool
Use Corneal Curvature Radius Diopter Reference when you need this image, stimulus, notation, coordinate, or observation component for supplied research data.
How to use the tool and how it works
- Enter radiusMeters, suppliedKeratometricIndex. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read referenceDiopters. Use the output convention below.
For positive radiusMeters and suppliedKeratometricIndex>1 return referenceDiopters=(index-1)/radiusMeters.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| radiusMeters | Radius Meters | Required. Finite number; strictly above 0. |
| suppliedKeratometricIndex | Supplied dimensionless reference convention, strictly above one. | Required. Finite number; strictly above 1. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| referenceDiopters | Reference Diopters | Required. Finite number. |
{
"input": {
"radiusMeters": 0.008,
"suppliedKeratometricIndex": 1.3375
},
"output": {
"referenceDiopters": 42.187499999999986
}
}Limitations and assumptions
- Radius is meters and the index is a supplied keratometric convention, not automatically a material refractive index. This reference conversion does not measure corneal shape or validate optical power, lens selection, or clinical diagnosis.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use calibrated acquisition and a documented visual or imaging protocol for complete interpretation. Confirm the reporting notation, viewing geometry, image scale, and support of the underlying observations.
References
Similar or alternative tools
- Lens Base Curve Supplied Index Crosswalk
Same-curvature refracting-surface power under explicitly supplied indices, without selecting a lens base curve.
- Optometric Trial Frame Vertex Reference
Paraxial thin-lens vergence transfer F/(1-dF) through signed distance d, without a patient vertex-distance prescription.