Whenever I'm having dry or red eye I use good ol' Visine. The only problem with Visine is if ingested... It can give you major diarrhea and/or vomitting. I used to be a bartender and I heard horror stories of bartenders putting a few drops into a customers drink who they didn't like (being rude, bad tipper, etc.).
Anyway, I did a little search on Google for 'homemade eye drops' and I came across a couple websites that say to avoid them. Here is one: http://www.medscape.com/viewarticle/421501_6