Calculating the IOL (intraocular lens) for cataract surgery is a preoperative process of determining the optimal optical strength of an artificial lens using biometrics, which includes measuring the axial length of the eye, the curvature of the cornea (keratometry) and the anterior-posterior chamber, and then using specialized formulas (for example, SRK/T, Holladay, Haigisa) to predict the refractive outcome and achieve the desired vision (near, far) after surgery.
It takes into account the individual characteristics of the eye, the type of lens (mono-, multifocal, toric) and the implantation parameters to minimize postoperative error.