Can eye drops cause irritation?

Yes: Eye drops can irritate the eye due to the active ingrediants or the inactive ingredients and preservatives. The more you use drops the more irritating they can be. You can also have allergic reactions to any ingredient in eye drops which may present as irritation.

Possibly: All eyedrops that come in a recloseable container are required to contain preservative chemicals to prevent growth of bacteria and fungi. Some patients are sensitive to the preservatives more than the actual treatment part of the drops. Some medications are inherently irritating to a degree, but we may need to use them if their benefits outweigh their side effects.