This is the only two-part episode in the shows run.
At the time Bernard Fox played the first Dr. Occularis, he was also intermittently playing another doctor - Dr. Bombay in Bewitched (1964).
Throughout the presidency of Ulysses Grant, the capital of the Arizona Territory was Tucson; in 1877 the territorial government was moved to Phoenix. Previous capitals were Tucson (under the Confederacy), Fort Whipple and Prescott (until 1867). (see also Goofs)