Video
CVI: Visual Field Abilities
Learn about the various visual field issues that manifest with CVI, observable behaviors and compensatory skills, general ideas for accommodations, and current research.
Written by: Rachel Bennett
Access the video transcript.
At Perkins, we are a gathering place of ideas. The CVI visual behaviors synthesize current research and build on the work of leading theorists in the field. CVI is a lifelong disability and we want to ensure that all individuals with CVI are fully understood. The CVI visual behaviors are an ongoing need, they can change and they can improve for some, but the need never goes away. No one area is separated from the other—the CVI visual behaviors are highly connected and all can impact the individual with CVI at any time.
What is Visual Field Abilities?
When our eyes are in a fixed position straight ahead, the area that we see is called a “visual field.” Visual field loss happens when a portion of the visual field is absent. People with CVI can have a range of visual field deficits, depending on where the damage or interruption happens in the brain. For example, damage on the right side of the primary visual cortex in the occipital lobe may cause left homonymous hemianopia or field loss in the left side of each eye.
This CVI impact area encompasses visual field access (peripheral and central) as it relates to awareness, established and/or maintained attention, and recognition.
Some people with CVI may have:
- Increased visual attention and/or recognition in a specific field of vision.
- Clinically measured “full” visual fields but demonstrate functional difficulties and a reduction in visual field abilities when out in the real world.
- Strong central vision function but reduced peripheral vision or rely solely on their peripheral vision, resulting in decreased detail vision.
- Vision loss in a specific visual field.
Visual field access may be further impacted by: reduced contrast sensitivity, ocular motor challenges, visual motor difficulties, visual clutter, competing sensory stimuli, visual fatigue, and motion in the environment.
I have trouble with my lower visual field. I like things to be put up on a slant board so that I can see it better. I can see some things that are higher in my visual field, but it depends on which side it’s on. Higher up on the left is a problem.
Young adult with CVI
What are some compensatory strategies related to Visual Field Abilities?
Many with CVI build strategies to compensate for visual field loss and changes in visual field access in a given moment or situation. Some of these strategies include:
- engage in a whole-head movement when visually scanning
- move around a space or environment with an adaptive posture (head down, tilted left or right for example)
- use upper or lower limbs to gain tactile information (running heel down steps; using their foot to check the change in surface)
- use a white cane or other devices to support safe navigation
- rely on methodical search strategies
- rely on memory and familiarity to support travel
- hold onto the clothing or limb of a trusted adult while navigating both even and uneven ground
When I’m rested and happy, I see clearly except for the visual field loss. My acuity is fine. But, when I have visual fatigue, it’s like looking through a straw. I have an extremely limited visual field. It gets all fuzzy. Usually, when I’m not fatigued, it’s like looking through an empty toilet paper roll.
Dagbjört, an adult with CVI, from Why Music is My Vision
What are some look fors/questions when observing your child with CVI?
When it comes to observable behaviors around visual field access, some people with CVI may:
- have a full visual field that becomes reduced when fatigued or when confronted with increased visual clutter
- position their eyes to a particular side when viewing
- bump into door frames or other objects on one side
- fall off curbs or miss other subtle changes in depth
- miss content on one side of a book or food on one side of their plate
- tilt their head to a particular side
- demonstrates difficulty with stairs
Some questions for observation for individuals who navigate by walking and/or using equipment such as a wheelchair and/or gait trainer:
- To what extent is visual attention increased, decreased, or not present within a specific visual field or fields? To what extent does the visual field access reduce when fatigued or when presented with increased visual clutter?
- Does the person with CVI look down while walking/rolling through an environment? Do they rarely look down while walking/rolling? Do they fall off curbs or miss other subtle or not-so-subtle changes in depth?
- Do they turn their head to one side or turn away when attempting to look at an object? When they engage with items and materials, do they tilt or position their head a certain way? Do they watch TV while positioned upside down or lying on their side?
- Do they bump into doorways or other objects on one side? Do they bump into objects below eye level? Do they bump their head on objects above eye level?
- To what extent do color, motion, and light support attention in certain visual fields?
- To what extent does the person with CVI miss food on one side of their plates or content on one side of a book?
- If the person with CVI is a hand writer, does the writing tilt up or down or to the left or right?
- Is the person with CVI aware of objects on a table near them? Are they not aware of people standing next to them on a certain side?
It’s hard for me to get around sometimes. People cut me off in stores, especially when they come on the right side because I can’t see anything on that side. I am always surprised. I’m like, “Oh my god, where did you come from, I can’t see that?!”
-Chloe, young adult with CVI, from the CVI Voices video
What are some examples of adaptations and accommodations?
All accommodations must be based on assessment. The following are meant to inspire and provide a general idea. Accommodations and instructional approaches must be student-specific. Access is individual.
- Learning materials should be positioned in the most accessible visual field (right, left, upper, lower)—use assistive items (i.e., slant board, book stand, tablet stand, All-In-One board).
- A student must be permitted to alter their seating position to accommodate their visual field.
- Safe navigation must be a priority. Supports may include O&M services; mobility devices such as a white cane; removing obstacles from the floor; strategic use of color highlighting on changes in depth; allowing extra time as needed on stairs, in hallways, and outside.
- Favor the student’s stronger visual field during the instruction and use of communication systems.
- Draw the student’s attention to the identified inaccessible visual field through auditory or tactile cues.
Find more examples from a guide to common CVI IEP accommodations in the CVI Now IEP Guide.
When my son interacts with items or watches videos on his iPad, I can tell he’s favoring his upper right field. His head is tilted and turned toward the left. Sometimes he puts his head down on the table on his left side when playing with his toys. When walking and going up and down stairs, he never uses his lower field and uses his compensatory and blindness skills to navigate like his white cane, toe-tapping, holding on to me, or the railing.
CVI parent
Following the science
Connecting current research of the brain, our visual system, and CVI to better understand the CVI visual behaviors.
According to Chockron, Klara, and Dutton (2021), with a CVI, there can be a range of visual field deficits:
- “Cortical blindness (i.e., lack of all visual sensation despite the integrity of the eye)”
- “Scotoma (i.e., lack of visual sensation for a small portion of the visual field)”
- “Tunnel/tubular vision (i.e., concentric reduction of the visual field), or its opposite, retention of peripheral vision (i.e., loss of the central visual field, while the peripheral visual field is preserved)”
- “Homonymous lateral hemianopia (i.e., loss of the contralesional visual field), or quadrantanopia (i.e., loss of a visual quadrant), and lower visual field impairment (peripheral, complete, or manifest as degraded clarity.”
Research shows various ways visual fields can be affected: Lesions or dysfunction affecting the optic tracts, lateral geniculate nuclei, optic radiations, or primary visual cortices can cause visual field loss (Lueck & Dutton, 2015). The superior optic radiations can also be affected, causing lower visual field impairment, which ranges from being complete to solely rendering the feet invisible when walking (Chokron & Dutton, 2016).
Effects of visual field deficits may include impaired visual motor coordination and difficulties in reading and social interaction (Chokron, et al. 2021, Jacobson and Dutton, 2000; Fazzi et al., 2009; Pawletko et al., 2014).
Visuospatial neglect, or visual inattention, is the difficulty of detecting or acting upon visual stimuli on one side of space. This is different from visual field loss in that full visual fields are available, but the brain does not give the attention needed to be aware of visual stimuli in a specific visual area. The person with CVI may behave as if half of space on one side does not exist. For example, if there is damage or interruption to the right posterior parietal lobe, then there may be visual neglect or inattention to the left-hand side. Increased clutter and visual stimuli density can make visual neglect more severe (Nijboer and Stigchel, 2019).
References
Berryman, A., Rasavage, K., & Politzer, T. (2010). Practical clinical treatment strategies for evaluation and treatment of visual field loss and visualinattention. Neuro Rehabilitation, 27, 261-268.
Chokron, S. & Dutton, G. N. (2016). Impact of cerebral visual impairments on motor skills: Implications for developmental coordination disorders. Frontiers in Psychology 7(1471), 1-15
Chokron, S., Klara, K., & Gordon D. (2021). Cortical Visual Impairments and Learning Disabilities. Frontiers in Human Neuroscience 15, 573.
Lueck, A. H., & Dutton, G. N. (2015). “Intervention Methods: Overview and Principles.” A. H. Lueck & G. N. Dutton (eds). Vision and the Brain: Understanding Cerebral Visual Impairment in Children (pp. 497-536). New York, New York: American Foundation for the Blind Press.
Jacobson, L., and Dutton, G. N. (2000). Periventricular leukomalacia: an important cause of visual and ocular motility dysfunction in children. Surv. Ophthalmol. 45, 1–13. doi: 10.1016/S0039-6257(00)00134-X
Merabet, L. B., Mayer, D. L., Bauer, C. M., Wright, D., & Kran, B. S. (2017). Disentangling how the brain is ‘wired’ in Cortical (Cerebral) visual impairment. Seminars in Pediatric Neurology 24, 83-91.
Nijboer, T. C.W. & Van Der Stigchel, S. (2019). Visuospatial neglect is more severe when stimulus density is large. Journal of Clinical and Experimental Neuropsychology 41(4), 399-410.
Philip, S.S. and Dutton, G.N. (2014), Cerebral visual impairment in children: a review. Clin Exp Optom, 97: 196-208. https://doi.org/10.1111/cxo.12155
Roman-Lantzy, C. (2018). Cortical Visual Impairment: An Approach to Assessment and Intervention. 2nd ed., New York, NY: AFB Press.
