Description
For nonnegative recordedDistance and positive sourceToTargetFactor return distance=recordedDistance*factor.
Optical calculations distinguish lens power in diopters, prism notation, angular axes, geometric distances, and visual-acuity reporting scales. Sign conventions and length units are especially important when a formula combines power with decentration or vertex distance. A supplied model term is separate from a validated visual test or prescription.
For nonnegative recordedDistance and positive sourceToTargetFactor return distance=recordedDistance*factor.
When to use this tool
Use Visual Stimulus Distance Factor when you need this explicit optical, chart, frame, axis, or reference conversion with compatible supplied units.
How to use the tool and how it works
- Enter recordedDistance, sourceToTargetFactor. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read distance. Use the output convention below.
For nonnegative recordedDistance and positive sourceToTargetFactor return distance=recordedDistance*factor.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| recordedDistance | Recorded Distance | Required. Finite number; minimum 0. |
| sourceToTargetFactor | Source To Target Factor | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| distance | Distance | Required. Finite number. |
{
"input": {
"recordedDistance": 200,
"sourceToTargetFactor": 0.01
},
"output": {
"distance": 2
}
}Limitations and assumptions
- Factor is target length units per source length unit. Unit identities, stimulus placement, measurement accuracy, and clinical test conditions are not inferred or validated.
- 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 the appropriate complete optical or measurement model when a scalar term is insufficient. Verify power, axis, length, notation, and reference conventions before applying the result within a broader assessment.
References
Similar or alternative tools
- Visual Stimulus Angular Step
Convert a supplied research stimulus coordinate step under an explicit angular calibration, without an acuity interpretation.
- Optometric Chart Distance Acuity Factor
Scale an explicitly calibrated Snellen chart fraction for a supplied test distance.