What is the purpose of corneal topography in lens selection?

• A. Measures eyelid tension.
• B. Determines color of the lens design.
• C. Maps corneal curvature to guide base curve selection and toric or multifocal designs; helps predict fit and centration.
• D. Assesses tear film thickness only.

Answer: (C)

Corneal topography maps the surface curvature of the cornea, and that detailed curvature information is what guides lens design choices. By showing where the cornea is steeper or flatter across its surface, it helps you pick the right base curve and determine whether a toric soft lens (for astigmatism) or a multifocal design is appropriate. It also helps predict how well the lens will fit and stay centered, which is crucial for both comfort and consistent vision. This is especially valuable when dealing with irregularities or higher-order shape differences that keratometry alone can miss, so you can select a lens that aligns properly with the corneal surface. The other options don’t fit because corneal topography isn’t about eyelid tension, lens color, or measuring tear film thickness—its primary purpose is to map curvature to guide fit, centration, and design choices.