CVI for Assistive Technology Specialists

Written by: Lindsey Lush, M.Ed., TVI

What is CVI?

Cerebral/cortical visual impairment (CVI) is a brain-based visual impairment caused by damage or interruption to the visual processing areas of the brain. With CVI, the brain has difficulty recognizing and making sense of the visual world. CVI impacts every aspect of life. The CVI visual behaviors are a framework for understanding the impact of CVI on access and is rooted in current CVI research.

CVI is the leading cause of childhood blindness and low vision, but it is alarmingly underdiagnosed. Less than 20% of kids in the US have a CVI diagnosis. CVI often co-occurs with neurological, neurodevelopmental, or genetic conditions. Those with healthy eyes and without other conditions can still have CVI.

What is assistive technology (AT)?

Assistive technology encompasses a wide range of tools, devices, and systems designed to support individuals with disabilities in their daily lives, education, work, and social activities. These technologies aim to enhance independence, promote inclusion, and improve the quality of life for people with various types of disabilities, including physical, sensory, cognitive, and learning disabilities.

How might CVI impact our approach to AT?

When working with students with CVI, it is important to assess how a student will best access and interact with their curriculum and environment. Many students with CVI rely on assistive technology to interact with their environment, communicate, produce work, or access information. Assessing the assistive technology tools needed to perform these functions is a crucial aspect of a student’s educational programming.

When appropriately used, assistive technology is a tool which promotes independence, facilitates access to academic and recreation and leisure activities, and can enhance the quality of life for individuals with CVI. In many cases, students may require more than one system or access method for instruction and learning, and to reduce visual fatigue or fatigue in general.

A student typing an essay may suffer from visual fatigue if their screen is too bright, too dark, the font is too small, or they have been working for too long without a break. The student may need to use other access methods such as a screen reader in order to edit their essay.
A student who uses an eye gaze to communicate may lose access to the device and the ability to communicate if they cannot interact visually due to fatigue. It would be important for the student to have access to tangible symbols or even 2D pictures (if appropriate) to maintain and facilitate communication.
Assistive technology must be tailored to the individual’s sensory, visual, and developmental needs. Aspects of assistive technology may need to be adjusted on a daily basis depending on several factors, including the student’s needs, environment, and learning task.

When might you suspect a student has CVI within your work as an AT?

CVI has diverse manifestations and no two individuals with CVI are exactly alike. Here some examples of indicators and observations that might lead to suspecting CVI. If a student has:

a complex medical history, cerebral palsy or seizures
displays varying abilities to access visual information
relies on memory of the layout of a device rather than assessing visually
seems to struggle with accessing information when presented with competing sensory information

Learn more about when to suspect CVI.

What strategies might be helpful to use when working with students with CVI?

Ryan checking out a brailler at a Braille Literacy Month celebration with Lindsey Lush

Students with CVI have unique visual needs which require a tailored approach to the assessment, selection, and implementation of assistive technology. Informal and formal assessments are crucial in determining the efficacy of an assistive technology system, and allow for informed decisions about necessary modifications or alternatives.

Empower the student. Engage the student (when possible) in discussions about their AT experience, which provides valuable feedback, empowers the student, and helps them to understand and internalize that if something is not working for them, they can advocate for themselves and be part of finding a better solution.
Repetition and routine. Students with CVI often require repetition and routine to aid in acquiring new skills, including those related to AT. Consistency and regular practice are key to developing proficiency with a skill or concept. It’s important to note that determining the effectiveness of an AT solution may take time. Students might need to interact with new equipment or accessibility settings for several sessions, weeks, or even months before determining whether something is working.
Holistic approach. Students’ learning styles, ability to generalize information, and physical access to the technology are all important factors in learning how to use assistive technology.

Instructional adaptations

Using technology doesn’t always mean using a screen. For some, screens can be incredibly fatiguing.
Switch activated devices, like bubble tubes or vibrating mats, may provide access to incidental learning and concepts like cause and effect, on and off, or waiting.
- Non-visual access to technology is also important for students with CVI. Some examples of non-visual activities are switch-activated devices, audiobooks, and access to a screen reader.
Adaptive switches are a great way for students with CVI to interact with a variety of technology. Adaptive switches replace the need for a keyboard and mouse or other traditional methods of operation. Some switches can be activated with a light touch or a specific body part like a hand, a foot, or the head. Switches come in a variety of sizes, shapes, and colors and provide an important tactile component to a screen-related activity. A switch also allows the screen to be in the student’s best visual field, while the switch stays in a consistent location on the table or wheelchair tray.
Screen brightness is an important factor when working with students with CVI. This is a highly personalized preference which should be assessed and adjusted as needed. Many students with CVI prefer reduced white point settings, or decreased brightness, even though backlighting can be helpful. Remember: Too much screen time isn’t good for anyone!

Environmental adaptations

Lighting is incredibly important when working with students with CVI. Task lighting may be helpful for table top tasks in lieu of overhead lights. Some students may struggle with glare or get headaches from a bright screen.
When working with devices, it is important to have a simplified background. This is true for the media being used, but also the setup of the technology within the learning environment. Occluding screens are helpful in reducing a busy background or environment.
Noises in the environment can be very distracting for students with CVI. Some may benefit from sound reducing headphones or utilizing headphones to better access the audio of the media.

Collaboration ideas

An assistive technology (AT) specialist can play a crucial role in supporting students with CVI in accessing their curriculum. Collaboration between disciplines, such as SLPs, OTs, and TVIs is an essential component to providing a high quality education to students.

An AT specialist can recommend and implement technologies that align with assessment, considering factors such as the impact of clutter, motion, light, and color..
They can work with speech therapists to integrate communication devices that accommodate the visual processing challenges of CVI, such as using high-contrast symbols or simplified visual scenes, or the need to implement auditory and tactile approaches.
Collaboration with occupational therapists might involve selecting AT tools that support both visual, nonvisual, and motor skills, like tactile tools or touch screens with customized visual interfaces.
The AT specialist and TVI can jointly determine how to modify digital learning materials to match the student’s visual functioning level, perhaps using specific colors, reducing visual clutter, or incorporating familiar images.

This interdisciplinary approach ensures that assistive technologies are seamlessly integrated into the student’s overall educational plan, supporting their unique visual processing needs and compensatory skills and access across all learning environments.

Examples of AT tools

Students with CVI have unique visual needs which require a tailored approach to the assessment, selection and implementation of assistive technology. Below are a few examples of AT tools meant to inspire inquiry to match a need that arises in the AT assessment process.

A Power Select tool, a control unit for use with the Sensory Learning Kit, that features 4 outlets and two dials for customizing switches for communication.

Power Select from APH is a versatile tool which allows users to interact with electronic devices using switches. The device allows for direct, timed, as well as on/off input. This device can be used with up to four electronic devices such as bubble tubes, vibrating mats or massagers, lights, blenders, fans, or anything other device which has an on/off button. This device could be used to support developing cause-and-effect concepts and may be great exposure for recreation and leisure skills for complex learners.
Touch screen monitors come in a variety of sizes and can be used with any computer. Touch screen monitors may be a great way for your student to access the computer more independently.
InclusiveTLC is a resource for assistive technology geared towards students with disabilities, including visual and multiple impairments. The company offers software and a robust website with simple, high contrast pictures compatible with a variety of access methods like touch screen, single switch, two switches, eye gaze, and keyboards.
Cosmo Switches are highly versatile and customizable switches which can interact with bluetooth ready tablets and pcs. The switches allow for adjustments in touch sensitivity, color, brightness, light mode and function. They come with a free app which offers a variety of switch based activities. There is also a paid version of the app which offers even more activities. This video provides more concrete ideas and examples of the cosmos.
Accessibility features on devices or third party software (Zoomtext, Jaws, Fusion, NVDA, etc.): Computers, tablets, and third party software can provide a plethora of high quality visual and auditory accessibility settings, which can greatly alter the visuals of a screen, access methods, and functionality of a device. Fine tuning visual preferences and auditory access or other accessibility features can greatly increase independence, comfort, and access to assistive technology.

Explore more resources on CVI and PT

Note to readers: This article is meant as an overview and brief introduction to CVI, a deep and complex condition with diverse manifestions. It is important to remember that all children with CVI have different needs. The recommendations and suggestions are ideas for a starting point. There is not one size fits all approach for CVI, and interventions and strategies must be match to the student’s individualized needs and comprehensive assessment results.

Explore CVI overviews for various disciplines in our CVI Educator Toolbox.

Lindsey Lush, M.Ed., TVI

Lindsey Lush has worked at Perkins School for the Blind for over 20 years in many different capacities. Currently she is an Assistive Technology Instructor/TVI at Perkins Lower School serving students with visual and multiple impairments. She attended graduate school at University of Massachusetts where she earned her masters in education as a teacher of the visually impaired.