Go to previous article
Go to next article
Return to 2003 Table of Contents
Linda J. Burkhart
Children who face significant neurological challenges, may also exhibit difficulties using their vision effectively, due to cortical vision impairment. How do we help these children develop neurological pathways to enable them to make sense of what they see? How do we design adaptations and augmentative communication strategies to enhance vision development, cognition and communication?
Cortical vision impairment is diagnosed by functional visual disabilities. Typically, these children have a "normal" vision report from an ophthalmologist, meaning that their eyes are not damaged. However, observation of the child's behavior reveals lack of use, or limited use, of vision for functional activities. For these children, specific attention needs to be paid to building the neurological pathways that enable them to make sense of what they see. With appropriate and practical strategies for developing visual skills, integrated into daily routines, many of these children can improve their ability to process visual information and make sense of what they see.
Dr. Christine Roman, (Roman, In Progress) has delineated characteristics of children who have cortical vision impairments and developed strategies to assist with the development of vision. These characteristics may include: a normal eye report, light gazing, specific color preferences, movement assisting vision, latency of visual gaze, visual field differences, lack of interest in visual novelty, difficulties with visual complexity and distance viewing, absence of primitive visual reflexive responses, visual motor difficulties, and trouble with coordinating listening and looking.
Children who experience cortical vision impairment may have multiple challenges, including motor problems, cognitive delays, and difficulty with language and communication. These students present a unique set of challenges that require special considerations. Vision Specialists, who have experience with cortical vision impairment, should be an integral member of these children's teams. They will be able to conduct a functional vision assessment and help the team understand what strategies will assist vision for that child at given times in development of his/her vision.
Coordinating Listening and Looking:
Children who have an auditory strength, often choose to interact auditorily with their environment and may ignore visual information, thus loosing opportunities to develop vision. Many of these children can not pay attention to both auditory and visual information at the same time. When both are presented together, the child chooses to listen and not look. Understanding this can help us change the way we interact with these children and how we present materials. Sound can sometimes be used to attract visual attention, but then, if it continues, the child may look away in order to focus on the sound, thus shutting off the visual information. When talking, to children who have cortical visual impairment, we should get their attention and allow them to look first, before describing things to them, commenting or singing to them. Make sound a powerful reinforcer for looking. For example, instead of calling to a child when you enter the room, try to get the child to visually locate you before greeting her. In a similar manner, when showing pictures and picture symbols to a child, allow them to focus in visually before adding the verbal stimulus. For simple cause and effect experiences, try to provide some activities that allow for visual responses to the child's efforts. For example, try switch-activated animation and movement on a computer screen without sound, delayed sound, or a short sound at the beginning, silence for most of the animation, and then fun sounds at the end.
Movement Assists Vision:
Movement is often an effective way to increase visual interest. The young child's brain is wired to pay attention to movement. Using movement can assist the child in understanding the visual difference between an object and the background. By quietly shaking a toy or picture, the child will be more likely to look at it. This is in contrast to a child with a physical vision impairment of the eyes. Those children may have more difficulty seeing something that is moving. Using movement and animation on simple software programs, such as IntelliPics, can be an effective strategy to promote vision. Language play and simple communication activities can be designed in this way.
Latency of Visual Gaze:
Latency of gaze is often an issue. The child may take quite a bit of time to actually look at an object or picture. If the object is not kept in the same location long enough, the child may not have the opportunity to see it. Movement, without sound, such as shaking in one location, instead of moving through a wide area is more effective. This of course, is impacted by visual fields, which will be discussed below. With effective presentation of materials, visual latency can lesson over the course of an activity, as the child starts to "turn on" his visual channels. This should be encouraged. Just as vision can improve with use, sometimes the child's vision fatigues with intense use, and he may need a short rest from using his vision.
Visual Field Differences:
Differences in visual fields are another obstacle. In addition to being different, they often change. Sometimes a child may not see to one side or below or above a certain point. However, this can change from day to day and also sometimes change within an activity. As we present sign language or picture symbols or other technologies to these children, we need to carefully monitor the child's visual field and move the pictures or ourselves to areas where the child gives an indication that she can see. This is particularly important when presenting choices. Sometimes children can do better when both items are presented to one side, one above the other, and other times, items need to be presented at the same level, but maybe slightly above eye level. Observation of the child is your best guide. Motor challenges also effect the child's ability to maintain a gaze on an item and also to reach for an item. Being aware of these problems helps us be alert and observant of the child, so we can constantly monitor how we need to present materials.
Disinterest in novelty is a surprising characteristic. Unlike typical children, who are generally much more interested in new toys and sights, the child with cortical visual impairment, may completely disregard new sights and instead choose to look more at familiar spectacles. This is because the child has developed some neurological pathways to process what she has seen many times and she can make more sense of it. With new items, the child is overloaded and not able to relate what she is seeing to existing visual pathways. These new pathways must be built slowly over time, since the usual visual pathways may have been damaged. The child must constantly compare what she is seeing to information that already makes sense to her, in order to build these pathways. Consistency in how visual materials are presented is important, as well as frequency, and relating what is being seen to function. Special attention to symbol selection, presentation, and frequency should be considered in using Aided Language Stimulation (Goossens', Crain, Elder) which is a powerful way to build visual and auditory familiarity.
Another major challenge for children with cortical visual impairment is complexity. Items that a child can visually recognize may seem to disappear in front of a busy background or when placed with a group of other items. Complexity can overwhelm the visual system and then the child may not be able to process what he is seeing. Bringing items/pictures closer, placing them individually on a plain black background, and/or highlighting them with a flashlight are all strategies that will reduce complexity. Picture symbols with a single color are less complex than multiple colors on one picture. White symbols, with highlighted backgrounds (as recommended by Goossens', Crain, Elder) are a good choice to use with these children. When using pictures, allow the child to focus on them visually without auditory distractions and then point out what they are looking at in the picture to help them relate to what they are seeing.
Visual motor skills are often difficult for these children. Many will look and then look away when reaching, which makes coordination of the two challenging. This may be related to a motor reflex, or it may be a result of underdeveloped vision or both. If the child is using a communication system that relies on the coordination of vision and motor skills alone to select a communication message, the child may have considerable difficulty.
Create communication opportunities and strategies that allow the child to use auditory strengths, so that the child's language development is not held back by delayed visual skills. At the same time, make sure that there are plenty of opportunities to enhance visual skills, especially, when the child is not communicating. This is a tricky balance, because concentrating only on auditory skills, may mean that visual skills deteriorate. Most of these children do well with forms of partner assisted auditory scanning, tactile systems with voice-output, and auditory scanning on devices. Two switch auditory step scanning allows the child time to process information at her own pace, and to know when to look for the visual component of the system. Visually following someone's finger or a moving object along a scan, may be easier than following a succession of blinking lights. The idea is to provide the visual component, but not to require the child to rely on the vision to utilize a communication system. With the visual component present, over time, it may become less of a novelty and be able to be processed by the child. Being able to utilize both vision and hearing will, in the long run, give the child more options for communication systems. Being able to communicate effectively using auditory and/or tactile strategies, as soon as possible, will insure the child has the tools to develop language and communication.
Due to the unique characteristics of cortical vision impairment, careful planning and integrated strategies can have a major impact on the development of neural pathways for vision as well as provide children with effective learning and communication systems that can take advantage of the child's strengths.
Christine Roman, PhD, material from American Foundation for the Blind publication, in progress. romanc@Marshall.edu
Goossens', Carol, Crain, Sharon, and Elder, Pam. (1992). Engineering the Classroom Environment for Interactive Symbolic Communication - An Emphasis on the Developmental Period, 18 Months to Five Years. Southeast Augmentative Communication Conference 2430 11th Ave. North Birmingham, AL 35234
Go to previous article
Go to next article
Return to 2003 Table of Contents
Return to Table of Proceedings