What is the diameter of the contact area of the applanation tonometer?

The diameter of the contact area of the applanation tonometer is 3.06 mm. This measurement is significant because it relates directly to the principles of applanation tonometry, which is used to determine intraocular pressure by flattening a small, known area of the cornea. The specific diameter is essential for calculating the pressure accurately, as it helps establish the relationship between the force applied to flatten the cornea and the resulting intraocular pressure.

When the tonometer makes contact with the cornea, the standardized diameter ensures a consistent assessment across different patients. It is important for practitioners to understand this measurement as it factors into the calibration and operation of the tonometer, impacting the accuracy of the readings obtained during the eye examination.