Clinical Calculators

Chairside and research tools: vertexing, prism, acuity conversions, etc.

Vertexing

Contact Lens Vertexing

Calculate contact lens power from a spectacle Rx.

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Reverse Vertexing

Calculate a spectacle Rx from a contact lens Rx.

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Double Vertex

Calculate lens power given two vertex distances.

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Refraction & Cylinder

Plus-Minus Cyl Converter

Convert between plus and minus cylinder form.

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Retinoscopy

Convert neutralizing lenses and beam angle to plus/minus cyl.

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Amplitude of Accommodation

Convert cm to Diopters and compare to Hofstetter's norms.

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Visual Acuity

VA From Letter Size

Visual acuity from letter size and distance.

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Cycles/cm to VA

Visual acuity from cycles per centimeter and distance.

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Contact Lens & Cornea

Base Curve

Convert base curve units (mm and diopters) or use a chart.

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Javal's Rule

Estimated residual astigmatism from corneal Ks.

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Prism

Oblique Fresnel

Magnitude and orientation of oblique Fresnel prism.

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Simulators

Vision Simulator

Simulate astigmatism, cataract, diplopia, scotoma, and more on an eye chart.

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