High Quality Content by WIKIPEDIA articles! A pachymeter is a medical device used to measure the thickness of the eye`s cornea. It is used to perform Corneal pachymetry prior to LASIK surgery, for Keratoconus screening, LRI surgery and is useful in screening for patients suspected of developing glaucoma among other uses. Modern devices use ultrasound technology , while earlier models were based on optical principles. The ultrasonic Pachymeters traditionally have been devices that provide the thickness of the human cornea in the form of a number in micrometres that is displayed to the user. The newer generation of ultrasonic pachymeters. work by way of Corneal Waveform (CWF). Using this technology the user can capture an ultra high definition echogram of cornea, think of it as a corneal A-scan. Pachymetry using the corneal waveform allows the user to more accurately measure the corneal thickness, have to ability to check the reliability of the measurements that were obtained, have the ability to superimpose corneal waveform to monitor the change of patients cornea over time, and ability to measure structures within the cornea such as micro bubbles created in the cornea during femto-second laser flap cut.