Ryanair have dispensed with seat-back pockets, probably because they are one more thing to clean and cleaning takes time and time is money. Thus, no sick bags. So when your son wants to puke, what are you going to do? You call the flight attendant. Too late. Vomit hurled on to floor. Enjoy cleaning that up in your ten minute turnaround.
Ryanair bashing is pretty de rigeur nowadays, but the truth is they are cheap (£5 all inclusive return to Vienna), arrive on time, and run a new fleet of planes (sans sickbags).
A tip to avoid one of their more ludicrous charges:
Ryanair will sock you for a card charge per person per leg. (How are you supposed to pay? Mail them cash?) There is a workaround, though. Buy Ryanair vouchers (no charge), then redeem them against your flight.