Welcome to the Cristalens toric intraocular lenses calculator

This calculator helps you to select the best cylindrical power for an optimized correction of your astigmatic patients. It was designed for Cristalens toric lenses, and can be used only with the models ARTIS® T PL E and ARTIS SYMBIOSE®.

By choosing « Select an IOL » on this screen, you are agreeing the calculator conditions of use described below. You can decline these terms of use by closing the calculator.

Conditions of use:
The Cristalens toric calculator is exclusively intended for helping the user to determine the recommended Cristalens toric intraocular lens and the suggested axis of placement. The use of the present calculator is strictly reserved to healthcare professionals specialized in ophtalmology. Calculated values and informations are provided as a guideline only, and cannot be warranted. In no event will Cristalens be liable for any damages whatsoever arising out of the use of the calculator. The present calculator is owned by Cristalens, consequently the user may not copy, distribute or modify the calculator without Cristalens prior written authorization.

Warning about posterior corneal astigmatism:
During the calculation, you have now the possibility to include posterior corneal astigmatism (option enabled by default). The calculation of pre-operative astigmatism is then corrected according to the study reported by Ueno et al.[1] Click here to find more details about this update.
Be careful: you must disable this option if the device you use for keratometry measurements already takes into account posterior corneal astigmatism, for example with the "Total Keratometry" or "TK" function (in this case K1 and K2 are named TK1 and TK2). If you enable this option in the toric calculator, and if your measuring device also takes into account posterior corneal astigmatism, the combination of both corrections can then lead to overcompensation, and therefore to a non-optimal post-operative result.

[1] Corneal Thickness Profile and Posterior Corneal Astigmatism in Normal Corneas. Yuta Ueno, MD, et al. Ophthalmology 2015;122:1072-1078

Calculateur Toric

Cristalens Toric Calculator v4.1.1
UDI (01)03666217014840(8012)4.1.1
Eye selection
Pre-operative information










Pre-operative astigmatism:
0.00 D x 90 °




Total cylinder (at corneal plane):
0.00 D x 90 °

Computed toric iol
Recommended cylindrical power*:
IOL axis of placement:
Post-operative predictions
Cristalens toric IOL:
Expected residual astigmatism:
warningBe careful of astigmatism inversion (over-correcting)
warningBe careful, residual astigmatism is high (sub-correction)

Additional information

Surgeon information
Patient information
Delivery address

Summary diagram



The pre-operative astigmatism to be corrected is low, a non-toric IOL could be appropriate.
Do you still want to choose a toric IOL for this patient ?