Real Eye Motion is a Geometry Nodes setup for Blender that drives realistic character eye movement without keyframes. It can be applied to any character that has Eyelid and Eyeball bones, including rigs from Blender's Human Generator and Daz3D.
The setup covers several kinds of motion. Blinking runs on a random possibility, a random look point provides the main movement, and subtle eyeball shaking adds a secondary movement. The look point can also follow an object in the scene. Documentation is included with the product.
Real Eye Motion supports Blender 4.0 and newer, with listed compatibility for 4.3, 4.2, 4.1, 4.0, and 3.6. The developer notes it also works in Blender 3.6, though not at its best there. A demo video is available, and the product is listed as royalty free.