When first learning about CVI, I only was taught to focus on the child’s visual attention to light. This included looking at the visual attention to environmental light and to looking at the visual attention to lighted objects.
In the hundreds of assessments that I have done since 2002, parents and students have expanded my understanding of the multiple ways light can impact a child with CVI. Here is what I have learned so far from listening to those important voices, voices of people living with CVI.
Some children do have increased attention to environmental light: to lights in the ceiling and lateral light provided by lamps. Some have attention to windows and doors (which also tend to have the element of motion: moving leaves on trees, cars moving, people moving down hallways.) Some children have greater attention to lighted toys or to technology like iPads, iPhones and backlighted devices.
Some children have light sensitivities. They avoid light especially if it is too bright for them. Different spectrums of light can be bothersome such as the brighter sunlight outdoors. Certain light bulb spectral qualities are bothersome. Some children don’t like devices with light when it is too bright and they prefer dim backlighting. They report that backlighting eliminates their ability to see any objects placed on that backlighting.
Some children have difficulties with changing light levels. They stop at the entrance of rooms that are darker or at the entrance of rooms that are lighter. This makes leaving a bright room and entering a dark room or coming out of a dark room into a bright room very difficult. They often need to stop and adjust before moving forward into that new environmental light level.
Some children will avoid crossing reflected light on the floor or avoid and fear shadows on the ground.
In assessing a child with CVI, these are the multiple impacts we must consider since all have an impact on visual functioning.
Assessment of Light:
- For attention to light, we can eliminate light that is distracting to look at the visual attention to objects. For attention to light, we can see the impact of visual attention when using lighted objects vs non-lighted objects.
- For light sensitivities, we can interview parents and students for information and, in direct assessment. look at the child’s reactions to various light intensities.
- For reactions with changing light levels, we can ask parents and students but also observe the visual behavior in various environments with changing light level changes: entering a dark auditorium from a bright hallway or leaving a room to go outside in bright sunlight.
- We can assess the benefit of backlighting and ask ourselves: Does backlighting speed visual attention to the object or picture on it? Does backlighting allow the child to look at the object of picture longer? Does backlighting change the visually guidance of the upper limbs with improved and more accurate reaching using vision? Does backlighting improve reading comprehension, speed and sustained reading abilities? Does backlighting aid the child’s visual recognition of objects and pictures?
- We can watch a child’s reactions to shadows and reflected light on the floor. Do they stop and test with their foot? Do they walk around it? Are they fearful?
It is so important to remember that the brain of a child with CVI is unique. When that brain is impacted, we must be ready to learn exactly how that effects the child’s visual attention to and visual recognition for learning.
Think about how light might draws visual attention but don’t forget that very important consideration of light sensitivities, the difficulty with changing light levels, how light on the floor impacts navigation and whether certain backlighted light levels help or hinder learning.