Understanding CVI

Updated: Jul 26

It can be a difficult time for a parent or caregiver when their child is diagnosed with cortical visual impairment, often called CVI for short. It is also sometimes called cortical blindness. This diagnosis often comes after many other diagnoses and evaluations of disabilities. But CVI does not mean that your child will always be unable to see. In fact, improvement in functional vision is expected with intervention for CVI! You can work closely with your child’s team to make sure that CVI supports and interventions are a part of everyone’s treatment plan and part of your child’s daily life. You can also work with therapists to get specific tips on how to support intervention at home!

Cortical visual impairment (CVI), refers to visual impairment or blindness that is caused by an issue in the brain, not in the eye. Your child’s eyes may be healthy and traditional vision exams may come back normal, but the part of his or her brain that processes the visual information that the eyes bring in does not work correctly. The visual input is entering the eyes, but the brain can’t process it so that your child sees what is around them. CVI can have many causes and can be due to a challenge at birth or a result of a brain injury later in life. Many children with CVI have other disabilities as well.

It can be difficult to imagine what a child with CVI sees – it is not blurriness that many of us who wear glasses might be familiar with or the total blackness that we might associate with other types of blindness. The lines and colors of the world may appear clear, but the brain cannot process that information to recognize an object.

The image below simulates the visual processing of a child with CVI. Though you can clearly see the lines and colors of the image, visual recognition is challenging. Hint: look for a farm animal (scroll down to the bottom for the answer!).



What do you mean by “characteristics of CVI”?


When evaluating for CVI, experts often talk about the “characteristics of CVI.” These are behaviors that are associated with children with CVI.

  • Color preference – your child may have a favorite color to look at, often red or yellow

  • Need for movement – your child may only look towards objects that appear to be moving

  • Visual latency – there is a delay between when a toy is presented and when your child looks at the toy

  • Visual field preferences – your child may ignore toys in certain fields of vision

  • Difficulties with visual complexity – your child may struggle to see a toy when there is a cluttered background or lots of noise or stressful stimuli

  • Light-gazing and non-purposeful gaze – your child may stare at lights or appear to “look through” people or objects

  • Difficulty with distance viewing – your child may behave as though they are nearsighted

  • Atypical visual reflexes – your child may not blink when something moves towards their face quickly or something touches them between their eyes.

  • Difficulty with visual novelty – your child may prefer familiar toys and ignore new ones

  • Absence of visually guided reach – your child may have difficulty looking and reaching at the same time

Remember that these characteristics exist on a spectrum – some or all may be very obvious for some children, while others may appear to have only a few (though an expert in CVI may be able to identify more).


What can we do?


Intervention for CVI is most effective when it is early. When a child is younger, his or her brain is better at “rewiring” itself. With intervention, your child’s brain may build pathways for vision around the damaged areas in his or her brain to improve visual processing.

Intervention for CVI is very specific to your child. A therapist will look at the characteristics of CVI that they see in your child and provide visual supports to match these characteristics. As your child’s visual skills improve, the supports can be removed. This means that while providing toys in your child’s preferred color may be effective at the beginning of the intervention, the goal is to improve his or her vision so that they look at toys of ALL colors.

Your child’s vision may never be “perfect,” but through intervention, he or she can learn to use the vision they have to participate in all areas of daily life and increase independence!


There are three phases of CVI intervention:


  • Phase I — The goal of this phase is simply to get your child to look purposefully at toys and objects. Your child will probably need a very quiet space without bright lights overhead and good seating during this phase. Your child will be shown toys in the preferred color against simple backgrounds. You may have to wait a long time to give your child the chance to locate the toy.

  • Phase II — The goal of this phase is for your child to use their vision to make something happen. This may be turning on a toy with a switch, finding her cup to drink from, or moving beads to make a sound. The environment may still need to be very controlled. It’s okay if your child can’t look and reach for an object at the same time during this phase – this is a challenging skill!

  • Phase III — During this phase and throughout the intervention, your child’s characteristics of CVI will be evaluated. Phase III focuses on the skills that your child still needs to work on. Your child may work on looking and reaching at the same time. He or she may be able to use vision in complex and unfamiliar environments. New toys in different colors can be introduced.

Who should be on the team?


Many children who have CVI may have other challenges and diagnoses – their team may include occupational therapists, physical therapists, speech-language pathologists, physicians, teachers, and many others! A child with CVI should also have a Teacher of the Visually Impaired (TVI) with training in CVI to help educate you and your child’s team about your child’s current visual skills and how best to support them. Communication and collaboration between ALL team members are crucial – a child with CVI will be better able to learn new skills with OTs, PTs, and SLPs when their vision is considered!

What does that look like?


We at the BAC love to collaborate with each child’s team (it’s best practice, of course!) to provide individualized support to every kid we see. That means working with parents and TVIs to adapt the environment and task to build our target skills while also supporting a child's vision.

We know that the environment matters! Seeing the duck in the picture below when it is close and against a simple background is easy, but when it is further away and you must visually locate it against a cluttered background, it becomes more difficult. A child’s ability to use their vision may fluctuate widely based on the setting. Provide the supports that the child needs and remove them only when those visual skills have appeared. (Images from the CVI Complexity Sequences Kit)


Our treatment will change as a child’s visual skills improve. Take an important task like feeding, for example. While we may be working on self-feeding or drinking the whole time, the materials and environment will change to meet the child where their vision is. For example...

  • Phase I: Wrap shiny Mylar of the child’s preferred color around the child’s cup to both take advantage of the child’s favorite color and the appearance of movement. Present the cup to the child against a high-contrast, low-glare background, such as cardboard covered in black felt. Intervention should take place in a quiet area without bright overhead lights directly above the child. The child’s back should be facing any windows. Utensils should be consistent with each session and be presented one at a time. The child’s visual attention to the cup is the goal of this phase – decreasing latency and increased purposeful gaze are signs of improvement. Looking at the cup would result in the child being given the cup and drinking.

  • Phase II: The cup should remain wrapped in Mylar and should be presented like in Phase I, but the focus of this phase is to encourage the child to reach for the cup in order to drink. This intervention phase reinforces that looking at and reaching for the cup results in a drink. A child in this phase of the intervention may not be able to look and reach at the same time. They may visually locate the object but look away when reaching. This will be addressed later in intervention and should be allowed during Phase II. An occupational therapist can note the quality of the visual motor and fine motor skills that can also be addressed in combination with CVI intervention.

  • Phase III: During the final phase of CVI intervention, the occupational therapist can target the unresolved characteristics of CVI. Mylar can be removed and novel utensils may be introduced. Sessions can slow introduce sensory distractions until the child can eat lunch in the cafeteria with other students or eat independently with their family. New and complex backgrounds can slowly be added. During this phase, the child would be challenged to look while reaching (move the cup so the child cannot locate and then look away to grab it).

Resources for parents and caregivers

  • Webcasts about CVI by Dr. Christine Roman-Lantzy at http://www.perkins.org/resources/webcasts/cvi-and-the-evaluation-of-functional-vision.html

  • Cortical Visual Impairment: An Approach to Assessment and Intervention by Dr. Christine Roman-Lantzy

  • Webcasts about CVI by Ellen Mazel at http://support.perkins.org/site/PageServer?pagename=Webcasts_Cor­tical_Vision_Impairment

  • Texas School for the Blind and Visually Impaired website at http://www.tsbvi.edu/cvi-exercise/cvi-intro

  • America Printing House for the Blind website at http://www.aph.org/cvi/index.html

  • http://www.littlebearsees.org/

  • CVI Perspectives Video through America Printing House for the Blind (DVD)

  • Your child’s teachers and therapists! You are all on the same team (your child’s) so work together to es­tablish clear communication to help each other support your child!

Remember our mystery farm animal?



When correctly oriented and color outlined, the image is easily recognized as a cow. Keep in mind that you benefit from the visual memory of what a cow looks like — your child born with CVI is forming these visual representations and memories for the first time!


Written by Boston Ability Center Occupational Therapist, Lauren Mazel, OTD, OTR/L

Resources

  1. Boot, F.H., Pel, J.J.M., van der Steen, J., Evenhuis, H.M. (2010) Cerebral visual impairment: Which perceptive visual dysfunctions can be expected in children with brain damage? A systematic review. Research in Developmental Disabilities, 31, 1149-1159.

  2. Guzzetta, A., D’Acunto, G., Rose, S., Tinelli, F., Boyd, R., & Cioni, G. (2010). Plasticity of the visual system after early brain damage. Developmental Medicine & Child Neurology, 52, 891-900.

  3. Lanners, J., Piccioni, A., Fea, F., & Goergen, E. (1999) Early intervention for children with cerebral visual impairment: Preliminary results. Journal of Intellectual Disability Research, 43, 1-12.

  4. Matsuba, C.A. & Jan, J.E. (2006). Long-term outcome of children with cortical visual impairment. Developmental Medicine & Child Neurology, 48, 508–512.

  5. Newcomb, S. (2010). The reliability of the CVI Range: A functional vision assessment for children with cortical visual impairment. Journal of Visual Impairment & Blindness, 104, 637-647.

  6. The Optometric Extension Program Foundation. Renshaw Cow Card/Mystery Picture. Retrieved from http://www.oepf.org/product/renshaw-cow-cardmystery-picture.

  7. Roman-Lantzy, C. (2007). Cortical Visual Impairment: An Approach to Assessment and Intervention. American Foundation for the Blind Press, New York.

  8. Tsai, L-T., Meng, L-F., Wu, W-C., Jang, Y., Su, Y-C. (2013). Effects of visual rehabilitation on a child with severe visual impairment. American Journal of Occupational Therapy, 67, 437–447. http://dx.doi.org/10.5014/ajot.2013. 007054.

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