Binocular stereo acuity affects monocular three-dimensional shape perception in patients with strabismus

Area of Science:

• Vision science
• Neuroscience
• Perception psychology

Background:

• Strabismus affects binocular vision and depth perception.
• Understanding 3D shape perception in strabismus is key to visual rehabilitation.

Purpose of the Study:

• To evaluate 3D shape perception in strabismus patients.
• To determine the roles of stereopsis and monocular cues in this perception.

Main Methods:

• Twenty-one strabismus patients (with/without stereo acuity) and 25 controls identified 3D shapes using monocular cues (shading, texture, motion) and binocular disparity.
• Participants also discriminated elementary features of these cues.

Main Results:

• Patients without stereo acuity showed greater errors in 3D shape from shading and texture compared to controls.
• Strabismus patients with and without stereo acuity had deficits in 3D shape perception from binocular disparity.
• No group differences were found for 3D shape perception from motion cues.

Conclusions:

• Binocular stereopsis is essential for fine 3D shape perception, complementing monocular cues.
• The findings highlight the perceptual benefits of binocular stereopsis in strabismus.
• Potential interaction of visual cues in ventral occipitotemporal regions is suggested.