I've been meaning to make this tutorial for a while!
This is how I make fursuit eyes. There really isn't a wrong way to do things as long as it looks good, is durable, and provides good vision though, so don't take this as an end-all, be-all method. Experimenting is half the fun of making costumes!
Hopefully the infographic provides enough explanation, but if you have any questions, definitely feel free to ask.
Here are some places to get the supplies needed for these:
Buckram (paintable fine mesh fabric): [link]
Never bought from this store, but it looks good.
Plastic sheets: [link]
I have bought from here and I can vouch for the quality. .03-.04 thickness is what I prefer, any thinner and it warps with the heat from the hot glue. Any thicker and it start becoming really hard to cut.
Suede for eyelids: [link]
My secret to this? Swatches. Buy whatever fur you need for the costume and grab a swatch of the suede you want for the eyelids for a nominal fee. Their swatches are plenty large to get a pair of eyelids from. :3
The acrylic paint can be bought at any craft store, you don't have to go expensive with this. Same with paint pens.