Primary objective of this study is to evaluate and compare the measurements of two different optical biometrics systems in patients who will undergo cataract surgery or presbyopia surgery using intraocular lenses (IOL-PC).

This is a prospective study including patients visiting the outpatient Ophthalmology clinic of the University General Hospital of Alexandroupolis, who suffer from diagnosed cataract or presbyopia and are going to undergo implantation of intraocular lenses surgery. The patients will be fully informed about the procedure and the purpose of the study and a written informed consent will be provided by all participants. They will then undergo an ocular biometry examination using two optical biometric systems, Argos (Alcon Laboratories, Inc.) and IOLMaster 500 (Carl Zeiss Meditec AG). IOL Master 500 (Carl Zeiss Meditec AG) is a non-invasive optical biometer that uses partial coherence interferometry (PCI) with a wavelength of 780 nm to measure the AL of the eye. Argos (Alcon Laboratories, Inc.) is a novel non-invasive optical biometer that uses swept source optical coherence tomography (SS-OCT) with a wavelength of 1050 nm. The measurements of the two systems that will be compared are the axial length, the keratometry values, the anterior chamber depth (ACD), the horizontal corneal diameter (white to white \[WTW\]) and the lens power in diopters (D).