The total length of the eye from the cornea to the retina.
Biometry and Intraocular Lens (IOL) power calculations are the cornerstone of modern cataract surgery, transforming the procedure from simple lens removal to a precise refractive intervention. The goal is no longer just to restore sight, but to achieve "refractive neutrality" or a specific target vision without the heavy reliance on glasses. The Role of Biometry Biometry & IOL Power Calculations - PDF
Measuring "Total Corneal Power" (both the front and back of the cornea) is essential for Toric IOLs, which correct astigmatism. The total length of the eye from the cornea to the retina