I tried making eyes with it, but it's hard to keep it from making bubbles. I've taken a liking to Zerovoc resin, which is meant for glassing surfboards but it casts pretty well too. It's a single part UV curing resin, a bit of a different critter from EasyCast. It's much cheaper ounce for ounce though. The only caveat is that the mold needs to allow UV light through it for best results, though if you cured it slowly (like with sunlight) it would probably be fine in anything. I use a high power UV lamp, which tends to cure the surface too quickly and leave the inside uncured, so it only works with UV transparent molds. The sun isn't predictable enough here to count on it.

Back to EasyCast, Daryl is right about it being very persnickety about ratios. (All two part resins are) You have to get
exactly equal amounts of the two parts. It's much easier to work with than polyester resins though, which don't use equal ratios. If the ratio isn't exactly right though, you could get casts that are cloudy, sticky, or bubbly. If you do decide to use it, make sure you do so in a ventilated area - it has fumes and smells pretty bad, though again not as bad as polyester resins. Stir slowly to minimize bubbles. If you still get bubbles, a heat gun works wonders. The resin will thin when it gets hot, and the bubbles float right out. I've heard of people using matches and lighters to do the same thing, but I'd be afraid of scorching the resin.

Your breath will pop bubbles at the surface too.
Here's a test eye I made with Zerovoc:
http://snowfox102.deviantart.com/art/Resin-eye-experiment-175400767And here's a video about casting with EasyCast. She's making eyes too, for costumes:
http://www.youtube.com/watch?v=rD8bkxyFVQE