(ophthalmometer) n. an instrument for measuring the radius of curvature of the cornea. Usually the vertical and horizontal curvatures are measured. All keratometers work on the principle that the size of the image of an object reflected from a convex mirror (in this case, the cornea) depends on the curvature of the mirror. The steeper the curve, the smaller the image. The keratometer is used for assessing the degree of curvature of the cornea in different meridians. —keratometry n.
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