Subtle Eyes, formerly "Subtle Cyborg Textures",  is a collection of iris and/or eyeball texture replacements. All subtle, all cool. It includes intricate circuitry for the aspiring cyborg, or more natural beauty for the organic model wannabes. There will be conflicts between this mod and other mods attempting to change the texture of base eyes. However, this mod should not affect eye recoloring.

There are a lot of resources on the Internet that are helpful for designing things. If you want to make something, it's good to check out the resources.