Lasik in October created a need for eye drops, though the Refresh recommended brand by objective measures performed poorly.
Cappable: If the individual vials can be re-closed by snapping the twist off top. This lowers the evaporation rate, chance of contamination, and overall cost. With a cap, vials last for a few uses. Refresh is the only brand that isn’t able to be re-capped. If drops are used to completion, this is relevant and prevents waste, though if as they package directs they are used a single time, being cappable is not relevant.
Active Ingredient: Dextran lowers viscosity, though this didn’t seem any less thick than water. Glycerin eyedrops would seem to be thicker, though in this case the slipperiness can be felt, and the liquid does seem to be any closer to a gel. Glycerin seems to try and keep moisture in the eye, though used before bed, upon waking there is a small amount of “gumminess” and this is the only eye drop to leave a perceivable residue near tear ducts, whereas all others seem to wash the eye. All seem to contain various salt compounds (sodium chloride, potassium chloride, magnesium chloride, calcium chloride) and will as such leave a very fine powder if enough dries on the skin or eyelashes. Glycerin leaves a residue closer to a flaky glaze.
Price: Name brand things can be expensive, and in this case, Refresh costs the most and is not a better performer. Equate is the best value, and the Revive Plus vials and performance are identical to the more expensive Walgreens (Lubricant Eyedrops). Even during a Walgreens sale on the aforementioned item, Equate still came out on top.
mL/Vial: Larger vials are a better value monetarily. Smaller vials are worth it if vials are used once instead of until empty.
Drop Size: Due to the smaller opening, the larger vial Walgreens (Artificial Tears) produces less surface tension at the contact point with the drop, and seems to have smaller drops. Note that though this may be better if one doesn’t need as much lubrication, the vial is easier to accidentally squeeze and waste drops from.