Three-dimensional display

A 3D display is a type of visual display that allows viewers to perceive depth in the generated imagery. It does so using depth cues based largely on focus and stereopsis.

To get a 3D display to show proper accommodation cues AKA focus, there are multiple ways. The two main ways are holographic displays and light field displays. A holographic display uses interference patterns to construct light as wave-like movements in an electric field that reach the eye. A light field display sends focal stacks of images based on rays to the eye.

Multifocal displays are displays that show multiple focus images at the same time, so that the eye can choose what to focus on.

3D is more than just stereoscopic flat images. For a few hundred years, people thought that stereoscopic flat images formed all of 3D vision.