There is a positive correlation between corneal thickness and IOP. The thicker the cornea, the higher the IOP measured, but there is no specific value for the correlation. It is generally believed that a corneal thickness of about 50 mm is equivalent to an IOP of 3 mmHg. If the measured corneal thickness is thicker, it may be possible to calculate the current IOP of the patient by comparing it with the difference in corneal thickness of a normal person. Whether the IOP is high or low compared to a normal person can be determined by comparing the corneal thickness to the IOP conversion formula. The normal range of IOP is clinically considered to be between 11-21 mmHg, and the average corneal thickness of a normal person is in the range of about 520 mm, so the converted IOP can be compared within the normal range of IOP.