|Pros|Cons|
|---|---|
|1 Manifold object, 1 Material, No clutter|Can't change pupil size|
|100% Real-time, BGE friendly|Low res (not for close up viewing)|
|Colorable iris|Inaccurate reflections around eye's cornea|
|Iris refraction|Cornea is sensitive to any geometry deformation|

***
[Real-time eyeball](https://youtu.be/vSXdZF5GUYo) with faked reflections and iris refraction. Big thanks to [Binary](https://blenderartists.org/forum/member.php?50556-Binary) on Blender Artists for his amazing [IBL node setup](https://blenderartists.org/forum/showthread.php?328835-IBL-node-setup-in-BGE-Viewport), thanks to which I was able to get object space reflection mapping. Also thanks to [proxe](http://www.blendswap.com/user/proxe) here on Blendswap for his awesome CC-Zero [Eye Texture Pack](http://www.blendswap.com/blends/view/41227).

I'd like to credit the author of the enivronmental equirectangular church image, but I can't figure out where I got it, since I've had it for a very long time. If anyone knows who made it, I'd appreciate if you told me so we can credit the author.
***
**Note:** If you've put the eye into your scene and the textures are glitching out for you, be sure to turn off World space shading under the shading options panel.