Preservatives are a very controversial issue with eye sprays. After all, they help kill germs and protect against infections. On the other hand, they can also irritate the conjunctiva and cornea and also damage them in the long run.
There are also preservatives that disrupt the stability of the greasy film, leading to further dry, irritated eyes.
It is not absolutely necessary for eye sprays to contain preservatives, as the development of germs is considered a very low risk.
However, the disadvantage with eye sprays without preservatives is that the spray should be used up within the specified time frame after opening. (10)