Diopter Conversion Calculator

Convert between different vision measurements including diopters, sphere-cylinder notation, and visual acuity measurements.

Input Parameters

Calculation Results

Calculation Results

Enter input values and click Calculate to see results

Calculation Formula

Formula will be displayed here based on conversion type

Where:

Diopter Conversion Calculator Usage Guide

Learn how to use the Diopter Conversion Calculator and understand vision measurements

Diopter Conversion Calculator Features

This calculator helps in converting between different vision measurements used in eye care:

1. Diopter to Sphere-Cylinder Conversion

Diopters represent the refractive power of the eye lens. This conversion estimates the equivalent sphere-cylinder notation which is commonly used in eyeglass prescriptions.

How to use: Select "Diopter to Sphere-Cylinder" and enter the diopter value. The calculator will provide an approximate sphere-cylinder notation.

2. Sphere-Cylinder to Diopter Conversion

Sphere-cylinder notation includes three components: sphere (SPH), cylinder (CYL), and axis (AXIS). This conversion estimates the total refractive power in diopters.

How to use: Select "Sphere-Cylinder to Diopter" and enter the sphere, cylinder, and axis values. The calculator will provide an approximate total diopter value.

3. Visual Acuity to Diopter Conversion

Visual acuity is measured as a fraction (e.g., 20/20), where the denominator represents the distance at which a person with normal vision can see clearly.

How to use: Select "Visual Acuity to Diopter" and enter the visual acuity in proper format (e.g., 20/20). The calculator will provide an approximate diopter value.

Understanding Vision Measurements

Diopter (D): A unit of measurement for the refractive power of the eye lens. It indicates how strongly light is bent as it passes through the lens.

Sphere-Cylinder Notation: The standard format for eyeglass prescriptions that includes:

  • Sphere (SPH): Corrects nearsightedness (negative values) or farsightedness (positive values)
  • Cylinder (CYL): Corrects astigmatism (the irregular curvature of the eye lens)
  • Axis (AXIS): Indicates the orientation of the cylinder correction in degrees

Visual Acuity: Measures how clearly a person can see. Normal visual acuity is typically 20/20, meaning a person can see at 20 feet what an average person can see at 20 feet.