Answer:
The accommodation of the eye and stereopsis.
Step-by-step explanation:
Using the visual system/perception, depth perception allows you to perceive the distance from an object.
Additionally, depth perception is critical in viewing the world in 3 dimensions.
The accommodation of the eyes is the cycle which they see at different distances, objects and have visual, vivid pictures of them by convergent and divergent beams of light.
Stereopsis allows you to visually apprehend/perceive the world in 3 dimensions (linking back to my previous statement of why depth perception is acute in understanding this).
3D is length, width, and depth.
Together, both these factors play a significant role in depth perception.