DISCLAIMER : Physicians are solely responsible for the IOL power choice before cataract surgery. By using the PEARL-DGS Calculator, the user agrees to waive all claims against and hold the authors (Dr Debellemanière, Dr Saad and Dr Gatinel) harmless from any claims arising out of his/her use of this tool. The PEARL-DGS calculator outputs are not intended to serve as surgical instructions.

If you want to evaluate the formula, do not enter the calculations by hand... we will be happy to perform them for you. Please write at We will ask you : the 5 biometric parameters (AL, K, ACD, LT, CCT), the IOL model that was used, and the mean postoperative refraction of the dataset (to adjust the constant). For post-operative surgery eyes, the type of surgery must also be provided.

Remember that this calculator and the methods that it uses are, by many ways, experimental.  This is especially true for the post-refractive surgery calculations, calculations using the data of the first operated eye, and/or combination of those features. ALWAYS DOUBLE-CHECK YOUR CALCULATIONS USING DIFFERENT FORMULAS.

The PEARL-DGS calculator was developed using the methodology described in the paper "The PEARL-DGS formula: the development of an open-source machine learning-based thick IOL calculation formula", by Debellemanière G, Dubois M, Gauvin M, Wallerstein A, Brenner Luis F, Rampat R, Saad A, Gatinel D. Am J Ophthalmol. 2021 May 13:S0002-9394(21)00276-2. doi: 10.1016/j.ajo.2021.05.004.

The source code of the methodology used is available at

We do not store calculation data.