Investigation of the Perception of Three-Dimensional Geometric Figures from the Rotational Movement of Their Two-Dimensional Image in Children with Ophthalmopathology

Manifestations of the illusion of a three-dimensional structure appearing when rotating a flat projection of a three-dimensional object (structure from motion (SfM)) were studied in three groups of children aged 7 to 17 years: 1) 40 children of the control group with orthotropy, the normal state of visual functions (including binocular and stereovision) and fundus; 2) 33 children with non-paralytic strabismus and normal fundus condition; 3) 50 children with non-paralytic strabismus on the background of congenital partial atrophy of the optic nerve (PAON). As a test image, we used the figure of a hexagon with diagonals passing through its center, presented in binocular and monocular observation conditions in the form of a still image, and when it rotates at a speed of 5, 10, 15, 20, 30, 40 rpm. It was shown that the perception of a three-dimensional structure in the form of a cube is possible with a stationary presentation of a test image in 2–3% of children of both the control group and groups of children with strabismus in binocular and monocular observation conditions. When rotating the test image in both binocular and monocular observation conditions, the number of children who perceived the cube in all groups increased with increasing image rotation speed, reached maximum values at 15–30 rpm and significantly decreased at 40 rpm. In the control group, during the transition from binocular observation conditions to monocular, the number of children perceiving the image as a cube significantly increases at rotational speeds of 5 rpm (p = 0.023), 10 rpm (p = 0.005), 20 rpm (p = 0.002) and 30 rpm (p = 0.001). In groups of children with strabismus (both on the background of normal fundus and on the background of PAON), binocular and monocular indicators were statistically comparable (р > 0.05). Comparison of indicators in different groups demonstrated a greater number of children perceiving a three-dimensional figure in the control group than in both groups of children with strabismus at certain speeds of rotation of the test image (from 10 to 20 rpm). In groups of children with strabismus on the background of normal fundus and children with strabismus on the background of PAON, binocular and monocular indicators are statistically comparable for all image rotation speeds. There was no significant dependence of the nature of the perception of the test image on age in all the studied groups of children. Thus, along with the general patterns of SfM manifestations in children of the studied groups, differences were revealed due to the nature of the interaction of monocular and binocular mechanisms of spatial perception in normal and ophthalmopathology. Thus, the SfM study can be used to evaluate the effects of depth and force relations of the monocular and binocular mechanisms of spatial perception in normal and ophthalmopathology.