Cortical Visual Impairment, often called CVI, is a brain-based visual condition caused by damage or differences in the visual pathways or visual processing areas of the brain. Vision loss in CVI does not originate in the eyes but in how visual information is processed neurologically.
Ocular visual impairments are linked to structural or functional problems within the eyes themselves, such as the retina or optic nerve.
CVI differs because eye exams can appear normal while visual functioning remains significantly affected.
Neuroplasticity plays a critical role in CVI. Young brains have the capacity to reorganize and create new neural connections, especially when targeted visual experiences are provided early.
Early intervention can support improved visual functioning and functional vision use over time.
The 10 Characteristics of CVI
Dr. Christine Roman-Lantzy identified ten characteristics that describe how Cortical Visual Impairment presents across children and across phases of visual functioning.
Characteristics may appear together or separately, and impact can change over time with targeted intervention and neurological growth.
1. Color Preference
Color preference refers to a strong attraction to specific bright colors, most commonly red, orange, or yellow.
Preferred colors require less neurological effort to process and often serve as visual anchors.
Objects presented in preferred colors are more likely to be noticed, fixated on, and visually sustained.
Use of preferred color can support visual attention, visual learning, and interaction with materials.
2. Need for Movement
Need for movement describes stronger visual responses to objects that move, flicker, spin, or reflect light.
Movement helps the visual system detect objects more easily than static items.
Toys that vibrate, objects that sway, or reflective materials often gain visual attention more quickly than still objects placed in the same location.
3. Visual Latency
Visual latency involves a delayed response when visual information is presented.
Children may require several seconds or longer before looking toward or responding to a visual target.
Latency does not indicate a lack of interest or inability to see but reflects slower visual processing.
Adequate wait time is essential during visual activities to allow processing to occur.
4. Visual Field Preferences
Visual field preferences describe consistent use of specific areas of the visual field, such as left, right, upper, or lower fields.
Other areas may be avoided or ignored. Objects placed in preferred fields are easier to locate and sustain visually.
Awareness of field preferences supports effective positioning of materials and communication partners.
5. Difficulty with Visual Complexity
Difficulty with visual complexity includes four related forms that affect visual access.
Object complexity refers to the difficulty in processing objects that have many details, colors, or patterns.
Array complexity refers to the difficulty of locating one item among multiple items or in cluttered environments.
Sensory complexity refers to reduced visual attention when competing sensory input, such as sound, movement, or touch, is present.
Facial complexity refers to the difficulty in recognizing faces due to high detail, subtle movement, and constant change.
6. Need for or Attraction to Light
Need for or attraction to light involves fixation on light sources or improved visual attention when objects are brightly illuminated.
Light can act as a visual cue that draws attention and supports detection.
Some children may visually attend more consistently when light is directed toward objects or materials.
7. Difficulty with Distance Viewing
Difficulty with distance viewing reflects stronger visual performance with objects positioned close to the child.
Visual access decreases as distance increases.
Near viewing allows larger visual images and clearer processing, while far viewing may require more neurological effort and result in reduced accuracy or attention.
8. Difficulty with Visual Novelty
Difficulty with visual novelty involves reliance on familiar objects, environments, and routines.
New or unfamiliar items often require repeated exposure before visual recognition occurs.
Familiarity reduces visual complexity and supports efficient processing, allowing children to use vision more consistently.
9. Absence of Visually Guided Reach
Absence of visually guided reach involves difficulty coordinating vision with hand movement.
Children may look at an object and then look away while reaching, or reach without visually confirming hand placement.
Vision and motor systems often function separately until visual-motor integration develops.
10. Atypical Visual Reflexes
Atypical visual reflexes include reduced or absent protective blink or threat responses that typically develop early in infancy.
Lack of these reflexes reflects neurological differences in visual processing rather than a lack of awareness.
Presence or absence of reflexes may change as visual functioning improves.
How to Diagnose CVI?
Diagnosis of Cortical Visual Impairment relies on three core criteria that must be considered together rather than independently.
No single test confirms CVI. Accurate identification depends on a pattern of neurological history, observable visual behaviors, and characteristic visual responses.
Neurological History
Neurological history provides critical context for diagnosis.
CVI is associated with injury or differences in brain structures responsible for visual processing.
Medical records often reveal events or conditions that disrupt typical visual pathway development.
Presence of one or more of these factors increases the likelihood of CVI, especially when visual behaviors do not align with eye health findings.
Atypical Visual Behaviors
Atypical visual behaviors must be observable and cannot be explained by ocular conditions alone.
Standard eye exams may show healthy eyes, yet functional vision remains impacted.
- Inconsistent visual attention across settings or times of day
- Strong reliance on movement or specific colors to notice objects
- Difficulty locating objects in cluttered or visually busy environments
- Variable visual responses influenced by fatigue or sensory load
Patterns of behavior over time provide more diagnostic value than isolated observations.
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Presence of CVI-Specific Visual Characteristics
CVI-specific visual characteristics confirm that visual challenges stem from brain-based processing differences.
Characteristics reflect how visual information is interpreted neurologically rather than the clarity of sight.
Identified characteristics align with known CVI patterns such as visual latency, field preferences, difficulty with complexity, and reduced visual-motor integration.
Recognition of multiple characteristics strengthens diagnostic confidence.
Use of the CVI Range
Assessment frequently uses the CVI Range, a functional vision evaluation scored on a scale of 0 to 10.
Scoring reflects how consistently and effectively vision is used in everyday activities.
Lower scores indicate greater neurological impact on visual functioning, while higher scores reflect improved visual access and integration.
Three phases describe visual functioning levels across the scale:
| CVI Phase | CVI Range Scores | Visual Functioning |
|---|---|---|
| Phase I | 0–3 | Severe visual impact with brief or inconsistent visual use |
| Phase II | 3–7 | Moderate visual functioning with emerging skills and growing visual curiosity |
| Phase III | 7–10 | Visual functioning is closest to typical, with challenges remaining in visually complex situations |
Movement across phases varies for each child and may occur unevenly across visual characteristics.
Continuous assessment supports accurate planning and adjustment of intervention strategies.
CVI as a Spectrum
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CVI exists on a spectrum rather than as a single presentation. Each child experiences a different combination of characteristics with varying intensity.
Assessment across the CVI Range helps identify current visual functioning and guides intervention planning. Progress may occur unevenly across characteristics.
Intervention strategies must align with both the phase level and individual visual characteristics to support functional vision use.
Read more: Ever asked yourself what do blind people see?
Summary
CVI is a brain-based condition that affects how visual information is processed rather than what the eyes can physically detect.
Every child with CVI presents with individual patterns of strengths and challenges shaped by phase level and characteristic profile.
Early identification using the CVI Range allows personalized intervention to begin as soon as possible, supporting visual growth and functional outcomes.