I am very sorry to hear about this incident.  You would have a cause of action against the department store for your damages, if you can prove that you contracted the pink eye infection while having your make up done.  This would be very difficult to prove.  First, I would suggest you research the incubation period for pink eye from time of contact with the bacteria to the actual manifestation of the infection.  It might be more than a few hours.  If you can show that you contracted the pink eye infection at the department store, you could seek reimbursement from the department store for your damages, which would include your medical costs, lost wages from work and any other damages you might have such as costs of a babysitter.  Good luck to you.