The eye is very sensitive - the cornea has the highest concentration of sensory nerves of any tissue. So pain can persist almost for no reason. Perhaps the eyedrops they are talking about are an anti-inflammatory, such as prednisolone (which you may or may not have been given to use in the first week after surgery). I wouldn't shy away from calling them back and asking for the information - you've got a right to know.
If it helps, you can use more artificial tears. I'd suggest preservativefree to avoid further irritation. These are the expensive ones in the tiny vials. They say to use only once and then discard, but I save money by sticking the cap back on and have not had a problem (I'm careful not to contaminate by touching anything with the tip of the vial). A thicker over the counter ointment could help at night.
For peace of mind, nothing beats a second opinion.