Do you suffer from monocular vision or know someone who does? Have you ever wondered how people adjust to missing depth perception? According to Contact Lens King's article "Monocular Vision Impairment | Living Without Depth Perception", there are 5 monocular depth cues or visual cues that can be used to gain a better perspective on the depth and distance of objects. By becoming proficient in reading and understanding these depth cues a person is capable of approximating the actual distance objects are from each other.

Monocular Depth Cues

Monocular vision can be quite frustrating, however with the use of the following visual depth cues a person is able to evaluate and gain a relatively accurate measure of depth perception.

Linear Perspective Depth Cue

While viewing objects and their surroundings one might observe parallel lines. In these cases, these lines can be used as points of references to gauge the distance of objects relative to one another. By evaluating how parallel lines converge in the distance in respect to objects within those lines a person can develop a particular perspective on their relative depth to one another. Below is an example of how this type of monocular depth cue can be used.

Overlapping Depth Cue

Overlapping or interposition is another cue that can be used to determine spatial positioning of objects relative to one another. By simply being able to distinguish which of the objects is in front of the other, a person can immediately gain an understanding of the perspective to determine which objects are closer or further away. Here is an example of using overlapping as a depth cue in determining object positioning.

Texture Gradient

Paying attention to detail is important when using this cue. The premise behind this specific spatial cue is that being aware of the details of an object can be critical in determining its position. For instance, knowing that closer objects usually provide more detail than those at further distances can play a critical role. Here is an example of how one may use texture gradient as a depth cue.

Relative Size

By observing object attributes such as shadows a person can determine if objects are actually at different depths or different in sizes. This is an easy and useful cue to use when evaluating the depth of objects. Below is an example of applying relative size as a depth perception cue.

Motion Parallax 

This cue involves awareness of objects' movement in respect to each other. It uses the premise that closer objects will move faster than more distant objects when in motion, such as in the case of a car. For instance, while driving, the trees on the side of the road move faster that the mountains in the background. Here is an example of this depth cue.

Monocular vision can be a difficult disorder to adjust to however, the 5 monocular depth cues shown above can be used to gain some spatial orientation. The more cues a person uses in unison the greater the chances are of determining an accurate depth perception.