Contact Lens calculator

Practical toolbox to calculate the contact lens parameters.

Relax Optic Variation

Lag of Accommodation

(measured in 33-40cm)

Lag of near fixation

(with Schober Cross, measured in 33-40 cm how much Add is needed to get a regular test image)

Pupil size

(measured in room lighting)


NightFlex Relax

Use the practical Near test APP from Smart Optometry App to measure the Near Lag of fixation with children. Order now your free Promotion Code for the PRO Version.

Over-refraction calculation

Contact lens

Eyeglass power conversion

Contact lens

Corneal curve conversion

Sagittal height calculation

Zone 1

Zone 2

Zone 3

Last zone diameter corresponds to total contact lens diameter (ØTot)

Transposition Cyl+ / Cyl-

Axe present / Axe with stabilisation

(RGP) Power adjustment with BC changes on RGPs

Calculation of numeric eccentricity

Kreading (centre)

Peripherial keratometry @ 30°