Dry eye deal: two packs (56 vials total) of preservative-free Soothe artificial tears eyedrops $10.73 or less with S&S and $8 off coupon @ Amazon

There are plenty of artificial tear options nowadays, but preservative-free varieties are fewer in number. This may not be your preferred brand, and to each their own, but it’s one I like.
Link to 2-pack
Clip the $8 off coupon on the page and use the Subscribe & Save option; if you’re buying five S&S items in the category of "diapers, baby food and other select S&S items", you can get 20% off instead of the baseline 5% off, making this even cheaper— around $7.75 if my math is right.
In comparison CVS.com has a version of this that’s on sale right now (buy 1, get 2nd for 50% off) for about $20.00 if you buy two. Wal-mart has this product for $9.86 a box (~$19 for 2).