3D refers to anything that is three-dimensional, meaning it has a width, height, and depth (length). Our physical world is three-dimensional, and we spend our day moving in three dimensions. Humans have 3D perception, also known as depth perception, which enables us to perceive the spatial connection between things simply by looking at them. As we look around, the retina of each eye creates a two-dimensional image of our environment, which our brain then transforms into a three-dimensional visual experience. However, it's important to remember that seeing in 3D requires seeing with both eyes (stereoscopic or binocular vision). People who can only see with one eye (monocular vision) can still perceive the environment three-dimensionally and may not be aware of their stereo blindness. They simply lack one of the tools required for three-dimensional perception and are therefore dependent on others without being aware of it.
