Price 20$ on Unity Asset Store: https://assetstore.unity.com/packages/tools/animation/realistic-eye-movements-29168
But now you can download Realistic Eye Movements FREE.
Realistic Eye Movements v2.0.1
This easy to use component makes your characters more lifelike by animating their eyes, heads, and eyelids. It uses human movement data from published academic research to produce convincing eye animation.
It has additional support for usage in virtual reality (VR) projects and is used in VR titles such as Technolust. It is the code behind the VR demo Coffee without Words. It lets the character look at the player’s “social triangle”: each eye individually and the mouth region.
Realistic Eye Movements (REM) can control your character’s eyes, head and eyelid movements to make them look around, at the player, or at objects, in a lifelike way. You can use it with characters that have eyes rigged to a Mecanim humanoid bone rig or characters that just have two separate eye gameobjects. You can assign points of interest in the character’s environment for the character to look at, or let them just look around idly, or let them look at the player when the player comes into
view or keeps staring at them.
If your character was generated with Mixamo Fuse, MakeHuman, Autodesk Character Generator, MCS (Morph3D) or UMA, setup is as easy as just importing the corresponding preset with a few clicks. For other characters, setup is easy as well: just assign the corresponding bones or blendshapes and set a few eye positions like looking up or down.
You can let the character look around randomly, at the player, or at points of interest that you defined and which you can control. Works on desktop and mobile.
The asset comes with full source code.
unityassetcollection.com – Get all paid Unity Asset for free