Appointments Times Four

For the first year or so of my daughters' lives, appointments were easy. Well, not necessarily easy when you consider the work it took to bundle up four infants and take them to the doctor, plus coordinate our work schedules to get them there. But at least all their appointments could be done at the same time. Now, things are a little tricky.
Around age 3, the girls started developing different issues. Roo needed glasses, which required various follow-ups. Then Tortilla needed glasses. At first I could take them to their follow-ups together, but then Tortilla needed to go in more often to determine a) if her glasses were working and b) if she needed to wear a patch to prevent "lazy eye." Gone were the days of making six-month or one-year follow-ups on the same day for all four girls.
Then today things became even more complicated. At a follow-up appointment for Tortilla, the opthalmalogist decided Tortilla no longer needs to wear her glasses. Yippee!!! But she needs to go back in two months to make sure her vision is still "up to par" without glasses. Everyone else needs to be seen in six months. This particular opthalmalogist only sees patients in the mornings (I think she's actually the equivalent of a physician's assistant, but we are scheduled with her for routine follow-ups since they take less than a half-hour). Did I mention the girls will be in preschool four mornings a week starting in August? I can't pull just Tortilla out of class because I would never make it back to school in time to pick up the others. At this point I told them I would have to wait to receive the school schedule, figure out what days school is canceled, and then call to make my appointment.
I remember when I was in school it was common to arrive late or leave early for a doctor, dentist, orthodontist, etc. appointment. I'm not pointing fingers at these providers, but wouldn't it make sense to have appointments more conducive to patients and their parents? Very few providers have Saturday appointments... and those who do tend to only be there until noon. Sure, it's just preschool, but I have a hard time condoning constantly pulling my daughters out of school for routine appointments.
I realize this isn't just a "multiple thing." Parents with more than one child are constantly running from appointment to appointment. I would, however, much rather spend two hours at the pediatrician's office for our annual check-ups than have to go to four half hour appointments spread out over several days.
I have the next 14 years or so to figure this out, right? Maybe by the time my daughters are ready to graduate high school I will have figured out how to get all of them to their appointments without causing too much disruption to their schedules.