Easier to explain V3's eyeball materials in cross section. I've elected to use CorneaBulge and IrisOut in this diagram to make the materials easier to differentiate; by default the materials overlay each other almost perfectly and the cornea's curve replaces the eyewhite's missing front section. V3's eyewhites are partial spheres with the back 3rd cut off and the corneal area in front cut off. The pupil is a flat disk behind the iris and neither uses transparency. The cornea is the only part which uses transparency. Oddly enough the V3 MAT poses also give it the eyeball texture despite the fact that 100% transparency makes it irrelevant.