When Satish was almost one and a half year old, the family recognised developmental delay and enrolled him for early intervention services. As a Physiotherapist, I evaluated him for impairment that limits his functional abilities. I recognised that he did not process visual information well and started questioning his vision.
The only thing family knew about his vision that on ophthalmology evaluation his eyes were normal and Satish will improve his vision as he grows. However, it is not the case, research proves that it takes on an average of 3.7 years for a child to improve vision as the result of brain injury if the child is enrolled for functional vision stimulation. Many children in my caseload have a cortical visual impairment as the result of brain injury and families were quite unaware of it. Most of the families are not aware of the potential of functional visual stimulation in children with CVI and its influence on physical and cognitive development. With the intent of educating our families and professionals about cortical visual impairment, I have presented a brief information what is CVI and its characteristic behaviours.
Cortical visual impairment refers to a visual impairment as result of brain injury. Visual impairment due to physical problems with the eyes is different. In CVI, the physical health of the eyes may be normal i.e. eyes are able to see, but the brain is unable to interpret what the eyes see as the result of damage to visual centres in the brain. This means the in most cases of CVI, the eye examination will be normal, but remember CVI coexist with eye impairments.
Although there is much of a debate about how children with CVI respond visually, there are unique characteristic behaviours of CVI that can affect visual functioning at various degrees. Understanding these behaviours will guide us in planning effective intervention strategies for children with CVI.
Characteristic Behaviors that are unique to CVI (based on the works of Dr Christine Roman)
Color preference: – Child seems to look at certain colour (s). Usually red and yellow are the preferred colours but the child may visually attend to any other highly saturated colours. One of the children whom I treat has a strong preference for green colour. It is important for the families / Educators or therapists to identify child’s colour preference as it will assist in planning treatment strategies.
Movement Preference:- Most of the children with CVI require movement to visually attend to an object or a shiny reflective Objects (Shiny objects are considered as movements in the brain). For example, Child may visually attend to hanging toys, movement of screen clothes, a light behind a ceiling fan, pinwheel etc…
Delayed Visual response:- Children with CVI often take time to look an object. So it is important to provide sufficient time when presenting an object. The time delay these children show is often variable and depends upon the other characteristic behaviours.
Gazing and Non-purposeful gazing:- Children with CVI will stare at light; one of the classical feature seen in CVI. Even though this feature resolves as the child progresses in functional vision but quite evident in the initial phase of CVI. The children will constantly gaze at the window (sunlight) or the ceiling lights.
Visual Field Preferences:- Children with CVI will show preference to look in one particular direction. Most of them see better is presented in the periphery probably on one side more than the other. Satish prefers to use his vision only on the right side that has drastically affected the position of his neck and over a period develop asymmetrical neck. The position of his neck influenced his overall posture and feeding, think it all started with the vision. As the family understood and started working on his vision, his entire neck position and body posture changed. He now uses his neck in more symmetrical position.
Visual Complexity:- Most of the children CVI will have difficulty in seeing objects that are visually cluttered.
- It is easy for the child to see bright mono-coloured objects than multicoloured objects.
- It is easy for the child to see an object if the background is plain without any visual clutter. Satish’s mother stimulates his vision by showing him a preferred single coloured object while wearing a black colour dress
- It is easy for the child to focus on an object if the environment is noise free. Most of these children cannot see if there are noise in the environment.
Distant Viewing:- All most all the children with CVI will have problems in seeing things that are far.
The absence of visual blink:-We all blink our eyes when objects come too close to our eyes or touch our forehead between the eyebrows. This will be absent in children with CVI.
Difficulty in seeing Novel objects:- Children with CVI will have difficulty in seeing objects that are new to them. These children often prefer to see objects that are familiar to them. Satish can recognize objects that are green in colour, the reason because Satish room walls and curtains were green in colour, so this colour has become more familiar to Satish than any other colour.
Impaired visually guided reach:- Often children with CVI look away while reaching for the object. They cannot coordinate vision and reach together. One of my child Adhvi first locates an object in the visual field then turn away from it before she reaches for it.
Looking at these characteristics are a valuable guide for planning visual stimulation. Every Family of a child with Vision impairment because of brain injury should gain such insights to help their child to build a functional vision.
About the Author
Dr RM. Sundar Kumar
Certified Neuro-Developmental Therapist (NDTA, USA)
Trained Sensory Integration therapist (USC/WPS)
Dr RM. Sundar Kumar has 14 years of post-graduate professional experience in Physiotherapy. He is currently working as Consultant Paediatric Physiotherapist providing expert solutions to the families and children with Cerebral Palsy, Developmental Delays, Autism, Sensory Processing Disorder and cortical visual impairment.