Binocular Vision and Depth Perception

What is required for binocular vision?

The eyes must work together, converge or diverge, and have good acuity and control of eye movements.

What is the purpose of convergence in binocular vision?

Convergence measures depth by determining the angle of the eyes when focusing on an object.

What experiment is used to study depth perception in infants?

The visual cliff experiment.

What are monocular depth cues?

Cues that include perspective, relative size, interposition, motion parallax, accommodation, and gradients of textures.

What are binocular depth cues?

Cues that include convergence and stereopsis.

What does stereopsis depend on?

It depends on retinal disparity, where two images fall on non-corresponding parts of the retina.

What is crossed disparity?

It occurs when the lines of sight cross each other between the fixation point and the eyes.

What is uncrossed disparity?

It occurs for objects that are further than the fixation point.

At what age does stereopsis typically emerge?

Stereopsis emerges at around 3.5 to 6 months.

What is the significance of the preferential looking (PL) method?

It measures stereopsis by showing infants displays with apparent depth.

What happens to stereopsis development between 3 and 6 months?

There are dramatic alterations in visual cortex and the ability of eyes to work together, leading to detectable stereopsis.

What is the clinical impact of lack of stereopsis?

It may indicate amblyopia and/or strabismus.

What is the relationship between visual acuity and stereopsis?

Stereopsis is not limited by visual acuity alone; it develops independently.

What are some common occupations that require good stereo vision?

Pilot, architect, surgeon, dentist, baseball player, driver, and waitress.

What general activities require good stereo vision?

Driving, pouring, threading a needle, planning 3D objects, and catching a ball.

What visual disorders can compromise stereopsis?

Monocular visual acuity loss (amblyopia), constant strabismus, anisometropia, astigmatism, corneal opacities, and cataracts.

What is the significance of the separation of ocular dominance columns?

It occurs in the visual cortex and is crucial for disparity detection and the development of stereopsis.

What are clinical tests for stereopsis?

Tests include separation of images using spectacles, real depth separation, and prism separation.

What is the role of the visual cortex in binocular vision development?

The visual cortex undergoes changes that enable the eyes to work together and detect depth.

What is the typical age range for infants to show preference for depth perception?

Around 16 weeks of age.

What is the difference between pre- and post-stereoptic periods?

Visual acuity and pupil size differ, and infants show preference for different stimuli.

What is the effect of amblyopia on stereopsis?

Amblyopia can lead to reduced stereoacuity and difficulties in depth perception.

What is the significance of the FPL and VEP studies?

They assess stereopsis using random dot stereograms and measure disparity detection.

How does stereopsis improve after its onset?

There is a rapid improvement in stereopsis over the following weeks.

What is the typical stereoacuity achieved by 6 months?

Stereoscopic acuity reaches 1 minute of arc.

What is the role of Panum's fusional area?

It allows for some degree of eye misalignment without causing diplopia.

What is the importance of disparity detection in infants?

It is crucial for the development of depth perception and stereopsis.