Making an Eyeball with Just a Shader

3-Second Blueprint (English)

1. Partition tissue into distinct cells with Voronoi noise and sample directional vectors to add organic surface texture.
2. Define eyeball geometry via circle signed distance functions layered with marbled vein patterns and dot-product diffuse shading.
3. Apply smoothstep functions across radial distance for glossy specular highlights and across time for procedural blinking.