The side effects of Focusyn on Bart were shown with many small changes to him. When Bart is reading a book, a line below his cheek is added. Bart is later seen speed reading and his pupils are smaller. The animators were not sure if Bart's pupils should be bigger or smaller than normal. Kirkland said that there were many model sheets (pictures that help animators draw characters) "going back and forth over the fax machines". The animators made Bart's pupils smaller in the episode. When Bart is with a doctor, he swallows many pills. He was first going to swallow all of the pills in the jar, but the censors did not like it. Mark McGwire is a guest star for the episode. Mike Scully said that McGwire was "probably the biggest man" he had seen and that he "did a great job".