Optometry Transposition Calculator

Optometry Transposition Calculator

Enter value between -20.00 and +20.00 in 0.25 steps
Enter value between -10.00 and +10.00 in 0.25 steps
Enter value between 0 and 180 degrees
Original: -2.00 -1.50 × 90°
New Sphere Power: –
New Cylinder Power: –
New Axis Angle: –

Transposition Details

Transposition Type: –
Spherical Equivalent: –
Cylinder Sign Change: –
Plus Cylinder Form
–
Minus Cylinder Form
–

Power Distribution

Sphere Power
Cylinder Power
Total Power
-10 D 0 D +10 D

Common Transpositions

💡 About Lens Transposition

Lens transposition converts between plus cylinder and minus cylinder notation while maintaining the same optical power.

Formula: New Sphere = Old Sphere + Old Cylinder

Formula: New Cylinder = -Old Cylinder

Formula: New Axis = (Old Axis + 90°) mod 180°

Note: This calculator provides optical transposition only. Always verify prescriptions with qualified eye care professionals.

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Optical transposition calculator Convert Eyeglass Prescriptions Instantly

Convert eyeglass prescriptions instantly with this Optical transposition calculator. Easily convert plus to minus cylinder, adjust SPH CYL AXIS, and compute spherical equivalent.

Optical transposition calculator

Fast, Accurate, Professional & Plus & Minus Cylinder Conversion

The Optical Transposition Calculator is a powerful online tool designed for optometrists, opticians, optical students, and anyone working with eyeglass prescriptions. It converts lens prescriptions between plus-cylinder and minus-cylinder form with complete accuracy—instantly and without manual calculation. Whether you are rewriting prescriptions, checking lens powers, or learning optical math, this tool makes transposition simple, fast, and error-free.

What This Calculator Does

The calculator automatically performs optical transposition, converting prescriptions while maintaining the same optical power. It handles:

  • Plus-to-minus cylinder transposition
  • Minus-to-plus cylinder transposition
  • Axis adjustment
  • Spherical Equivalent (SE) calculation
  • Cylinder sign reversal
  • Detailed breakdown of results

This ensures the converted prescription is always optically identical to the original.

Key Features

1. Automatic Lens Transposition

  • Sphere Power
  • Cylinder Power
  • Axis Angle

It applies the standard optometry formulas:

  • New Sphere = Old Sphere + Old Cylinder
  • New Cylinder = –Old Cylinder
  • New Axis = (Old Axis + 90°) mod 180°

2. Supports Full Optical Ranges

  • Sphere: –20.00 D to +20.00 D
  • Cylinder: –10.00 D to +10.00 D
  • Axis: 0° to 180°

3. Real-Time Calculation

Results update instantly as you type — no need to click repeatedly.
Press Enter to calculate quickly.

4. Clear Plus-Cylinder & Minus-Cylinder Notation

  • Current (input) form
  • Converted form
  • Plus-cylinder notation
  • Minus-cylinder notation

Great for students, professionals, and lens labs.

5. Spherical Equivalent Calculation

It automatically computes the SE using:

SE = Sphere + (Cylinder ÷ 2)

Useful for:

  • Soft contact lens fitting
  • Refractive surgery evaluations
  • Vision screening tools

6. Power Distribution Visualization

Includes a stylish bar chart showing:

  • Sphere power
  • Cylinder power
  • Total optical power

This Calculator is Useful for Optometrists, Opticians, Ophthalmic technicians, Optometry students, Lens manufacturers, Vision science educators, Anyone needing accurate lens power conversion

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