Thanks for your response Paige.    I think the patients are plots because each patient is randomized to receive either once-daily or twice-daily dosing of across both eyes.The only possible combinations are (Eye 1; Eye 2):   (Low concentration once daily; High concentration once daily) (High concentration once daily; Low concentration once daily) (Low concentration twice daily; High concentration twice daily) (High concentration twice daily; Low concentration twice daily)   It is not possible to receive, for example:   (Low concentration once daily; High concentration twice daily)   What do you think?   ... View more

The plots are patients and the sub-plots are the left and right eye within each patient. The whole-plot factor A is a dosing regimen (once vs twice daily) and the sub-plot factor B is dose concentration (high vs low). Individual patients are randomized to dosing regimen and the left eye is randomized to dose concentration level with the right eye receiving the other dose concentration level. Level of myopia is measured in each eye over time, hence repeated measures. ... View more