Every drop in this category arrives in a small sealed vial holding one application. There is no preservative in the formula, because the sealed vial does the work a preservative does in a multi use bottle. Open it, use it, discard it, and the next one is untouched.
This is the widest preservative free selection we carry, spanning most of the major lubricant lines:
Frequency first. Vials are the format people move to when they are using drops several times a day, or when an eye care professional has told them to stay away from preserved formulas. For a bottle you open twice a week, a preserved multi dose bottle is usually the simpler buy.
Then thickness. Some formulas here are watery and leave vision clear immediately. Others, Celluvisc among them, are noticeably heavier. Thicker drops tend to suit evenings better.
Then pack size. Packs run from 20 up to 180 vials, so once you know which formula you are staying with, the larger packs reduce how often you reorder.
One thing to note: Lumify PF is a redness reliever rather than a lubricant, so it belongs to a different category of product despite sharing the vial format. If you wear contact lenses, check the label, and bring any questions about frequency to your eye doctor.