Keratometry

Keratometry is a diagnostic procedure that measures the curvature of the cornea — the clear, dome-shaped surface at the front of the eye. By determining the cornea's curvature, keratometry helps assess the degree and axis of astigmatism and is essential for fitting contact lenses, planning cataract surgery, and evaluating certain corneal diseases. The measurement is expressed in diopters and provides crucial information about how the cornea bends light as it enters the eye.

During a keratometry examination, you sit comfortably with your chin on a rest while looking straight ahead. The keratometer projects an image of a circle or ring onto your cornea, and the instrument measures how this image is reflected. By analyzing the reflection, the device calculates the cornea's curvature at its steepest and flattest points. The test is completely non-invasive, painless, and takes only a few minutes per eye. No special preparation is required, and you can resume normal activities immediately afterward.

Keratometry plays a vital role in several aspects of eye care. It is indispensable for fitting contact lenses, as the base curve of the lens must match the curvature of your cornea for proper fit, comfort, and clear vision. Before cataract surgery, keratometry measurements help calculate the power of the intraocular lens (IOL) that will replace your natural lens, ensuring optimal post-surgical vision. The test also helps diagnose and monitor keratoconus and other corneal disorders that cause irregular astigmatism.

While keratometry provides valuable information about the central cornea, it is sometimes combined with corneal topography for a more comprehensive assessment, particularly when evaluating irregular corneas or planning complex surgeries.

At International Eye Hospital, we use modern automated keratometers that provide fast, accurate measurements as part of our comprehensive eye examination and pre-surgical assessment protocols.