Creating a character is one thing but creating a character in 3d that has depth is another. In life, the eye is a window to the soul. Eyes show inner thought because they have depth to them. At some level we read the eye ball without even knowing how or why certain looks evoke an emotion. We can compare this to body language. We can tell when a human is feeling sad by looking at their "pose" and the way they move slowly and kind of careless.
But we can further more tell that they are sad by the way their eyes look and move. The eyes of this sad subject may be more wet because of tears and their movement may be slowed, maybe even timid. Also the eyes will kind of stare at something symbolizing a more focused inner thought. Believe it or not this is all common sense, your mind knows all of these things. However you may have never thought about it consciously.
As 3d artists we have the ability to create photo real images. In that case we must pay great attention to detail when it comes to relating the thought, or emotion that we’re trying to convey to our audience. One way to do this is to pay great attention to the eye ball. The most simplest form is a texture map on a sphere. In some small cases this is enough such as background extras, or characters that will be shaded in a special way etc.
However I tend to subscribe to the Pixar’s belief that the eye needs a lot of attention in order to convey life. To me, a lifeless eye can ruin an image. An artist can model a photo realistic head in 3d but it will look lifeless if the eyes lacks depth.
So how do we create depth? Well like i sad, a sphere with texture map works for some scenes especially if it’s a more cartoony or stylized character, and its even better if there’s a bump map as well. However looking at Pixar’s "A Bugs Life", we see a lot of depth in the eyeball. From this we can assume that they didn’t use a simple sphere with a texture map. In fact this suggests they’ve modeled the eye more physically correct.
Now I’m no surgeon so I’m not going to chart out the entire structure of an eye. I’m an artist so I’ll fake it. That’s what we do. One thing to remember is that if it looks good...it’s good enough.
Before we look at the eye. When I set out to figure out how to make a better eye for my characters i thought about dolls and the way their eyes were shaped and how they looked. You may find that this eye reminds you of older style dolls.