"Mind's eye" refers to the imagination or the ability to visualize things in your mind, even if you can't physically see them with your eyes. It's like having a mental movie screen where you can picture images, memories, or ideas.
The degeneration is taking place before our very eyes Sending optical signals into the passages of our minds (untold-arsenal.com)
Fling the doors to your child's minds eye open wide with a pile of Haba blocks, a handful of colorful marbles, and a plethora of sleek, sliding, gliding, ringing, bouncing, jumping accessories to choose from... your child's mind takes in a spectacular view! (ecochildsplay.com)