The anterior corneaCornea is the most important refractive surface of the eyeEye, responsible for more than two-thirds of the total dioptric power. Even very small changes in corneal curvatureCorneal curvature might have dramatic effects on visual acuity. Topography is the science that describes the characteristics of a specific location in detail. As clinical demands continue to evolve, new techniquesTechnique for corneal topographyCorneal topography have been developed over time, making it an indispensable tool in clinical practice today. This section provides an overview of the featuresPlacido-based corneal topography of Placido-based corneal topographyCorneal topography measured with the Topographic Modelling System 5 (TMS-5, Tomey Corp., Nagoya, Japan).