The IOPs of different strains are stable and reproducible over time. Mean IOP ± SEM is shown for the indicated strain at different times of measurement. The measurement times within a single year were separated by a few months. The IOPs of strains that were analyzed multiple times in the same year are listed in the chronological order that they were obtained with the earliest measurement on left. The sex [Male (M) or Female (F)], age (months), and number of mice (n) analyzed for the CBA strains are listed starting with the earliest measurement and ending with the latest: CBA/CaJ, F, n = 22, age 6–7; M, n = 11, age 2; CBA/CaHN, F, n = 16, age 3; M, n = 8, age 3. For BALB/cJ and C57BL/6J, all groups were male and primarily 3 to 4 months old. The number of mice analyzed at each time follows: BALB/cJ 8, 10, 11, 15, 18 and 14, C57BL/6J 10, 14, 21,40,40 and 42. Strain name CBA/CaHN-Btkxid/J is abbreviated to CBA/CaHN.