The cornea is the highly curved clear window on the front of the eye, right above the iris, the colored part of the eye. The cornea helps focus light on the retina and therefore plays a significant role in how well you see. As the curvature of this clear structure changes, both the way your contact lens fits and your prescription, can change. Understanding the curvature of the cornea is necessary to properly fit and prescribe contact lenses or spectacles.
The corneal topographer is a highly sophisticated computer that "maps" the front surface of the eye to show how curved it is. Abnormalities in the curvature of the cornea can help the doctor diagnose corneal diseases and determine the best fit for specialty contact lenses. This information can also help your doctor determine if refractive surgery is appropriate for you. This computer can also help monitor subtle changes on your cornea over time and can also be useful when determining the extent of damage in the case of an eye trauma.
The corneal topography analysis uses colors to create a model of the cornea. The map colors indicate how the cornea flattens and steepens (the valleys and hills) over its entire surface. The corneal topographer analyzes the shape of the cornea several different ways to help your doctor evaluate its health.