In this procedure anaesthetiic drops are administered into the eyes then using a probe in contact with the cornea, the cornea thickness is measured.

Nowadays, measurements can also be obtained without contacting the cornea thanks to instruments such as the pentacam and  anterior segment imaging of optic coherence tomography. Knowing the cornea thickness is important in the measurement of internal eye pressure with Goldmann applanation tonometry. It is an indispensable device in refractive surgery apllied particularly for the treeatmment of refractive errors.

Figure 1. Corneal pachymetry;  the process of measuring the thickness of the cornea.