Just wondering what the difference between artificial tears and eye drops are. Many people call them by the same name but I want to make sure I'm using artificial tears. Currently I'm using Systane lubricant drops... I would use preservative free but whenever I open up a vial I never use enough to warrant it and end up throwing more than half away so it doesn't get infected. What are some brands and options for artificial tears that are safe to use on a regular basis?