Tools for eye-care professionals

Calculators for the refraction room and the lens workshop, made for optometrists, opticians and eye doctors. They run in your browser: nothing you enter is sent or stored.

The refraction room

Check the chart and refine the refraction.

Retinoscopy calculatorFrom the gross retinoscopy result and your working distance to the net refraction.Open →Visual acuity and chart sizeSnellen, decimal, logMAR and ETDRS letters side by side, and the letter size for your test distance.Open →

Prescriptions and lenses

From the prescription to the contact lens and the finished spectacle lens.

Transposition and vertexPlus and minus cylinder, contact lens power per meridian and the optical cross.Open →Base curve and lap curvesFor surfacing: the lap curves, the thickness and the lens clock check for a prescription.Open →

Myopia

Follow a child’s refraction over the years.

Myopia management guideA child’s refraction by the IMI definitions, the risk factors and the follow-up interval.Open →

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Tools for eye-care professionals

The refraction room

Prescriptions and lenses

Myopia

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