Clinically normal eyes were found to demonstrate different magnitudes of ocular hypertensive response when subjected to identical concentration, frequency, and duration of topical application of dexamethasone 21-phosphate. The search for a response measure which maximizes the detection of this heterogeneity led to the selection of the change in applanation pressure after four weeks of topical application of 0.1% dexamethasone three times daily. In the case of this measure, the hypothesis that the data represent a single homogeneous population had to be rejected at the 1% level of confidence.1 Using the above measure, 80 subjects with clinically normal eyes were shown to demonstrate three distinct and statistically different levels of response: low, intermediate, and high. Table 1 summarizes the characteristics of each level; ie, the range encountered in the sample, the mean, and the standard deviation, as well as the number of individuals and percent of the sample that demonstrated