SS-OCT biometers measure ocular dimensions that are critical for IOL power calculations. Keratometry readings are important parameters needed to determine the exact IOL power. A number of SS-OCT biometers are available today, namely ARGOS® (Movu, a Santec company), IOLMaster 700 (Carl Zeiss Meditec), OA-2000 (Tomey Corp.) and EyeStar 900 (Haag-Streit AG). Each one of them employs a different approach to measure the corneal curvature which leads to slightly different readings.