Although good visual capacity is essential for children's learning, we have limited understanding of the various visual functions among school starters. In order to extend this knowledge, a small-scale study was undertaken involving 24 preschool children age 5-6 years who completed a test battery originally designed for visual impairment…

Loss of vision is believed to have a great impact on the acquisition of spatial knowledge. The aims of the present study are to examine the performance of individuals with visual impairments on spatial tasks and the impact of residual vision on processing these tasks. In all, 28 individuals with visual impairments--blindness or low…

The aim of this study is to examine the performance in coding and representing of near-space in relation to vision status (blindness vs. normal vision) and sensory modality (touch vs. vision). Forty-eight children and teenagers participated. Sixteen of the participants were totally blind or had only light perception, 16 were blindfolded sighted…

The term "mental rotation" refers to a mental process during which individuals "encode the spatial information into an image, rotate the image mentally, and then access the image in its new orientation." Spatial perspective taking is based on a mental rotation process of the self. In spatial perspective taking, individuals seem…

This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest…

This article describes the physiological mechanisms involved in three-dimensional depth perception and presents a variety of distance and depth cues and strategies for detecting and estimating curbs and steps for individuals with impaired vision. (Author/DB)

Comparison of 2 totally blind, 2 visually impaired, and 9 normally sighted children (ages 5-8) on tasks of visual perspective taking found that the totally blind children were older than the other children when they mastered the tasks, made the highest percentage of errors before mastery, and made different errors. (Author/DB)

This article reports on the ability of observers who are sighted and those with low vision to make time-to-collision (TTC) estimations using video. The TTC estimations made by the observers with low vision were comparable to those made by the sighted observers, and both groups made underestimation errors that were similar to those that were…

This article reports on a study of the spatial mapping skills of two totally blind, two visually impaired, and eight normally sighted children. Children were asked to point to familiar locations in and around their homes. Results suggest that blindness interferes with the development of spatial knowledge in which Euclidean directions between…

Retinitis pigmentosa (RP) causes restriction of the visual field, progressive vision loss, and night blindness. This article presents an overview of the most common problems in orientation and mobility (O&M) for individuals with RP, appropriate interventions, vision science discoveries related to RP, and the impact of RP on functional visual…

This study compared effects of visual occlusion on the motor and spatial learning of 28 legally blind adult males, half due to acuity loss and half due to peripheral field restriction. For both groups, occlusion appeared neither to facilitate nor impede motor learning but did significantly impair acquisition of spatial relations. Results have…

Eighty-eight children (either totally blind or with residual vision) estimated directions between landmarks in a large scale layout of objects. Children experienced the layout either directly by walking around it or indirectly by examining a tactile map. Use of tactile maps considerably facilitated the performance of the blind children. (Author/DB)

This study, involving 20 children (ages 6-12) with legal blindness or partial sight, explored the relationships between ability to read and performance on tasks which require the manipulation of figure/ground relations. Significant differences were found between fluent readers and poor readers/nonreaders on four of the six tasks. No age…

Young children with low vision tend to experience delays in cognitive development, motor development, and social skills because of insufficient motivation and opportunities to explore their environments actively. This literature review explores the resulting difficulties in acquiring practical knowledge and spatial/environmental concepts,…

The development of sensory and perceptual ability in infants is an important area of infancy research. This book reflects current knowledge of perceptual development and points to some of the many questions that remain unanswered. The book is divided into four parts. Part 1, "How the Visual System Develops: Normal and Abnormal…