TYPICAL CHARACTERISTICS OF CHILDREN WITH CVI
· This is a brain condition not an eye condition. The optic system of the eye is often fine and the eyes appear normal. Non use of vision can be:
· Avoidance behavior when over stimulated
- Protection from perceived threat
- Reaction to non-motivating environment
- Sign of stress
- Lack of recall of similar situations
- A difficulty in sensory integration
· Children often have normal eyes at birth, usually coordinated eye movements.
· Around age 2 they may be diagnosed with optic atrophy due to lack of stimulation. Strabismus may develop with age, if child has difficulties with motoric control.
· Residual vision is variable, inconsistent and fluctuating. The child may have visual field defects.
· Vision fluctuates based on health, strength, fatigue, medications, seizure, and environment (noisy distracting environment).
· Children often shake their head side-to-side trying to find their visual field, attempting to get their visual system going.
· CVI is like looking at an incomplete drawing –you may not see something initially, but when told what it is, you can see it.
· They may need to confirm vision by touching.
· Visual symbols such as the face may be difficult to recognize-may be due to scanning difficulties.
· Children may avoid eye contact. (Gaze avoidance) They might look to either side, look away or be using peripheral vision.
· Short visual attention and visual interest. Children can’t handle too much sensory input. They appear to be daydreaming.
· Children respond first to things in periphery before centrally.
· Children often have good motion detection. In fact moving objects are easier to see than stationary ones. In addition, children in motion may be more aware of objects in the environment.
· Color perception usually intact. Yellow, orange, purple and red are easily perceived. Use primary colors rather than pastels. Colors easier to perceive than shapes.
· Pupillary response is usually fine although students on seizure medications may have a sluggish response.
· Depth perception, concepts of space and distance are often difficult. Children may have difficulty reaching for or placing objects accurately. They may be aware of distance objects but not able to recognize them.
· Some children improve visually with age while others may not.
· Children have difficulty discriminating foreground/background or figure ground; therefore clothing under a clear wheelchair tray can be confusing.
· Staff clothing can be visually distracting; clothing should be plain not patterned.
· Visual gaze will increase when the child feels in control of the situation.
· Children may get close to things not because they are myopic (near sighted)-but to block out other things by getting close, so that the object fills the entire visual field.
· The midline might be a stressful area to work in – watch the child to see if this is a problem.
· Many CVI students are found to be farsighted.
· The children may close their eyes while listening because too much stimuli is offered. There may be too many activities and the children can do only one thing at time.