Visual Impairment Defined
The term ‘visually impaired’ can be used to describe individuals whose visual abilities range from having a great deal of useful vision to complete blindness. Various terms are used to describe individuals with visual impairments. Blindness, referring to the absence of usable vision, is often used to identify the condition of individuals who may be able to perceive light or images, but are not able to use residual vision for functional purposes. The definition used for the purpose of determining eligibility for required services, ‘legal blindness’, refers to a visual impairment resulting in a maximum visual acuity of 20/200 in the better eye after refractive correction, or a visual field of 20 degrees or less in the better eye.
For educational purposes, the definition of visual impairment encompasses the definition of legal blindness, but includes students whose visual acuities may be better than 20/200. According to IDEA (2004), “Visual impairment including blindness means impairment in vision that, even with correction, adversely affects a child’s educational performance. The term includes both partial sight and blindness” [IDEA Final Regulations, 2004]. Although a universally accepted definition does not exist, low vision has been described as referring to one “having difficulty accomplishing visual tasks, even with the use of prescribed corrective lenses, but who can enhance his or her ability to accomplish these tasks with the use of compensatory visual strategies, low vision and other devices, and environmental modifications”.
Students described as blind or visually impaired have diverse needs even though they share a common trait of some degree of vision loss. Any student who has limited access to visual information will experience difficulties in any number of daily activities. From an educational perspective, the degree of vision loss is only one of several aspects for consideration in assessment and program planning. These students display varying cognitive abilities, levels of independence and physical agility, and may or may not have additional disabilities.
Because visual impairment and blindness are low-incidence disabilities, a student with vision loss may be the only student with this disability in his or her school or community. Intervention for students who are blind or visually impaired is based on the degree to which they can access, incorporate and respond to sensory information.
Impact of Visual Impairments on Learning and Movement
Although not documented by physiological research, it has been estimated that approximately 80% of learning occurs through vision (Brasher & Holbrook, 1996). Without the richness of information provided by typical vision, the development of the child with a visual impairment can be adversely affected across many domains. This developmental difference occurs as a result of the limited extent and frequency of experiences with the environment, including interactions with family members and peers. Children who have visual impairments have decreased opportunities for incidental learning and are less likely to gather complete sensory information to interpret the world around them and make sense of their surroundings. These learners have a limited range and variety of experiences, and often lack control over their environments and themselves in relation to it. By relying solely on their other senses, they often miss vital information about their surroundings.
The influence of vision on the acquisition of information regarding the world is vast and varies based on the level of functional vision available to the learner, which can range from only light perception to the ability to read standard print. The visual system allows individuals to make sense of their world through the collection, organization, and interpretation of the sensory information it processes. Consequently, a lack of clear visual input can lead to variations in development and the extent of learning that occurs.
Areas at Risk for Delays in Development
Children who are visually impaired do not learn incidentally through visual imitation like their sighted peers. The ability of a child with a visual impairment to learn can be affected across the interrelated domains of development as a result of the lack of visual sensory input and inconsistent experiences with the environment. Areas at risk for delays in development due to the effects of blindness and visual impairment include cognitive, social and emotional, daily living, career and vocational, sensory and motor, and orientation and mobility skills, as well as the development of concepts, have been identified as areas of development most at risk when a child has a visual impairment.
In typically sighted children, concepts such as object permanence, object constancy, cause and effect, and categorization develop through infants’ use of vision as they interact with their environments. Without active participation in specific learning experiences targeted to develop these concepts, children with visual impairments may not develop the abstract thinking skills that lead to the understanding of their own influence and control over their environments. Additionally, the presence of a visual impairment can impede the understanding of specific concepts, including identification of objects, the relationship of objects in the environment, auditory comprehension and analysis skills, the use of language and communication, and the academic skills learned in school, such as literacy, mathematics, and use of reference materials.
Social and Emotional
The development of social and emotional skills occurs through a child’s interaction with others. The learner’s lack of personal experiences and participation with family and peers can negatively affect the development of social and emotional skills, particularly for a child with a visual impairment. This deficit includes development in the areas of knowledge of self, including human sexuality; knowledge of others; interactions with others; self-advocacy; and recreation and leisure. A child with a visual impairment may neglect to initiate contact with others or engage in social situations, resulting from an unawareness of social cues and decreased opportunities for social engagement.
Many children with visual impairments are socially affected by the limited experiences available for interaction with peers. For children with visual impairments, acceptance from peers can be hindered as a result of unusual behaviors or mannerisms, such as rocking and eye poking and the lack of social engagement by the child who is visually impaired. This situation can lead to further isolation and reduction in the possibility of opportunities for practice with social and emotional skills.
Daily Living Skills
The area of daily living skills consists of tasks associated with self-care and routines of life, such as personal hygiene, dressing, food preparation, housekeeping, money management, and use of community services. Children with typical vision begin developing in this area of growth early in life as they participate in the act of watching and absorbing the actions and behaviors of their parents, siblings, and others. In children whose vision develops typically, information gathered incidentally through vision is used to plan and execute movements and routines of daily life, such as brushing one’s hair or spreading butter on toast. As a result of their disability, children with visual impairments often have decreased incidental opportunities to gather information about the processes of completing daily living skills, and may routinely be offered only limited opportunities for involvement in household or personal routines. Consequently, children with visual impairments who do not receive adequate direct instruction in daily living activities may demonstrate deficits of skills in this area, including tying shoes, washing hair, preparing an afternoon snack, or making a bed.
Career and Vocational Skills
Sighted children acquire career and vocational awareness with little effort, since this information is readily available through visual observation. The child with a visual impairment, however, may be limited in his understanding of the career and vocational skills apparent to his peers. Through the probable exposure to only those careers personally encountered through one’s daily life, development in this area may include only knowledge of the careers of family members, school personnel, and direct service providers. Limited access to the environment reduces the learner’s awareness and opportunities for gathering knowledge of a variety of job possibilities, the association and contrast between play and work, and the age-appropriate awareness of a job application process.
Sensory and Motor Skills
Vision allows individuals to gather information about the environment and assists them in the synthesis of information from their other senses in order to interpret environmental cues. Through visual feedback elicited from movement, children obtain enticement for further movement. This motivation to move occurs as a result of reinforcement from a variety of sources, such as a mother’s facial expressions of encouragement or worry, sensory feedback interpreted by the body, and the cognitive judgments a baby makes to refine movements while repeatedly reaching for a toy in view, as well as the information gathered incidentally by watching others perform movements. Body movement, including the development of fine and gross motor skills and locomotion, develops in the course of repeated practice and refinement through the adjustment of movement. Without frequent opportunities for practice and the possible reluctance of a child who cannot visually make judgments to move through an unfamiliar environment, a child with a visual impairment can fail to learn skills in the area of sensory and motor development.
Orientation and Mobility
The acquisition of skills in the area of orientation and mobility encompasses the understanding of one’s self-placement and relationship within the environment, and the abilities to efficiently plan and safely execute purposeful movement through the environment in order to arrive at a desired destination. Orientation and mobility incorporates the motor and cognitive skills involved in the execution of physical movements.
A child with a visual impairment may lack the skills to fully understand and maneuver within his environment. This discrepancy can occur as a result of lack of experience, which can lead to difficulty understanding body concepts, carrying oneself with proper posture and gait, and even initiating and executing independent movement within environments meaningful to the individual.
Although it is possible for a child with a visual impairment to develop many of the same skills as a child with typically developed vision, many factors influence the occurrence and sequence of skill attainment. Parent support, specific instruction, the availability and use of specialized materials, meaningful experiences within the environment, and the development of compensatory skills play important roles. Through meaningful experiences with others and their environment, children with visual impairments can increase their opportunities for learning and development. Acquisition of orientation and mobility skills provides the means for increasing meaningful experiences, and therefore has the potential to impact cognitive, social, career, and daily living skills. As a result, it is critical that students with visual impairments be provided with appropriate instruction to meet their needs in orientation and mobility.
In order to participate fully within the educational environment, students who are blind or visually impaired require instruction in disability-specific skills. These disability-specific skills are known as the expanded core curriculum