How Vision Problems Can Skew Psychoeducational Testing

November 18, 2025
​​​​​​​Man Kin (Eric) Chow, OD, FAAO, FOVDR

How Vision Problems Can Skew Psychoeducational Testing

 

Visual processing and binocular skills can quietly distort test results

Psychoeducational testing is designed to provide a deeper understanding of a child’s learning profile—how they process information, problem-solve, and perform across reading, writing, and math tasks. However, what if a child’s difficulty lies not in understanding the material, but in seeing the test accurately?
 

Many of the most widely administered assessments like WISC-V, NEPSY-2, Beery VMI, and TVPS-4, are visually demanding. They require children to scan, copy, decode, and manipulate visual information efficiently. When a child has undiagnosed visual challenges, such as tracking deficits, poor eye teaming, or delays in visual processing, the results may reflect these hidden obstacles rather than their true intellectual potential.
 

In this presentation, we will review sample pages from each of these tests to illustrate how children with visual difficulties perceive and experience them. We will break down how specific visual skills: accommodation (eye focusing), vergence (eye teaming), and oculomotor control (eye tracking) directly impact performance on psychoeducational assessments, while explaining these concepts in practical, easy-to-understand terms.
 

Recognizing and addressing these visual factors is crucial. When visual-spatial, visual-motor, or visual processing weaknesses are present, they should be identified and treated, ensuring that a child’s true cognitive abilities are accurately represented and supported.
 

WISC-V Coding and Symbol Search Subtests

The Coding and Symbol Search subtests of the WISC-V (Wechsler Intelligence Scale for Children, Fifth Edition) are designed to measure a child’s processing speed, visual-motor integration, and attention to visual detail. These tasks require children to quickly scan, identify, and reproduce symbols—skills that depend heavily on how efficiently the visual system gathers and processes information.  So it is clear that weaknesses in these areas may suppress performance, especially under timed conditions. Let’s take a look at

 

This is what someone with oculomotor dysfunction may experience this page:

 

 

Oculomotor skills refer to the coordinated eye movements that allow a person to accurately track, fixate, and shift their gaze between targets, enabling clear and efficient visual processing.  The include the following subskills:

• Saccades: Quick, precise eye movements from one symbol to the next. If saccades are inaccurate or delayed, a child may lose their place or skip items.
• Fixations: The ability to keep the eyes steady on a symbol long enough to identify it correctly. Poor fixation can cause blurred or double images.
• Pursuits: Smooth, coordinated eye movements that allow the eyes to follow a moving object accurately. Efficient pursuits help maintain continuous visual contact with a target. If pursuits are poorly developed, a child may overshoot, lag behind, or lose track of moving stimuli—impacting tasks like reading across a page or following a ball in motion.

 

NEPSY-2 (A Developmental NEuroPSYchological Assessment, Second Edition)

Another common psychoeducational test is the NEPSY-2 test. It is a comprehensive test designed to evaluate various cognitive functions in children ages 3 to 16. It assesses domains such as attention, memory, language, visuospatial processing, sensorimotor skills, and social perception. The results help identify learning difficulties, developmental delays, or neurological conditions by pinpointing specific areas of cognitive or visual-motor weakness that may affect academic and daily functioning.
 

Here’s an example of a test page of NEPSY-2 Letter/Number Naming subtest. The purpose is to evaluate how efficiently a child can visually scan, recognize, and verbally name letters and numbers arranged in rows. It is primarily a measure of rapid automatic naming, processing speed, and visual scanning efficiency—skills that rely on smooth, coordinated eye movements and strong visual attention.

 

This is what someone with accommodation difficulties may experience
 

 

 

Accommodative skills refer to the eye’s ability to efficiently and accurately change, sustain, and relax focus when shifting between near and far objects, ensuring clear vision during activities like reading or looking from the board to a notebook.  There are different type of accommodative issues:
 

• Accommodative Insufficiency (AI): The eyes have difficulty stimulating accommodation (focusing up close). Children may complain of blurry near vision, eyestrain, or fatigue when reading.

 

• Accommodative Infacility (AF): The eyes struggle to quickly shift focus between near and far targets. This causes lag when copying from the board or switching gaze between distances.

 

• Accommodative Excess (AE): The eyes over-focus and have difficulty relaxing accommodation, even when viewing distant objects. This can lead to headaches, distance blur, or eye discomfort after reading.

 

• Ill-Sustained Accommodation: Focusing starts out normal but cannot be maintained over time. Near tasks initially look clear, then gradually blur after sustained effort.

 

• Unequal Accommodation (Accommodative Asymmetry): One eye focuses differently from the other, leading to visual imbalance, fatigue, or intermittent blur in one eye.

Beery VMI (Beery-Buktenica Developmental Test of Visual-Motor Integration, 6th Edition)

The Beery VMI evaluates how well a child can integrate visual perception and motor coordination—essentially, how effectively the eyes and hands work together to reproduce visual forms.

During the test, the child is shown a series of increasingly complex geometric shapes (starting with simple lines and progressing to intricate designs).

The child’s task is to copy each shape as accurately as possible in their test booklet.
 

The test includes three core components:

1. Visual-Motor Integration (VMI): Copying the shapes themselves—measuring coordination between vision and fine motor output.
    
2. Visual Perception (VP): Matching shapes without drawing—assessing how accurately the child can visually discriminate between forms.
    
3. Motor Coordination (MC): Tracing within narrow boundaries—focusing purely on fine motor control.

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Here is an example of a test page from Beery VMI:

This is what someone with binocular or vergence difficulties experience
 

Vergence skills refer to the coordinated inward and outward movement of both eyes that allows them to align on a single point and maintain binocular vision and depth perception at various distances.  There are different types of vergence issues:
 

• Convergence Insufficiency (CI):  The eyes struggle to turn inward for near work. Common symptoms include double vision, eye strain, headaches, or words “moving” on the page while reading.
• Convergence Excess (CE): The eyes turn in too much at near distances. This often causes headaches, blurred near vision, or difficulty maintaining clear focus when reading.  Fun fact: Dr. Chow had this condition.  
• Divergence Insufficiency (DI): The eyes have difficulty turning outward for distance viewing. Patients may experience intermittent double vision at distance, especially when tired.
• Divergence Excess (DE): The eyes drift outward more than normal when looking at far targets, sometimes appearing as intermittent exotropia. Distance blur or double vision can occur, while near vision may remain normal.
• Fusional Vergence Dysfunction (FVD): The eyes can converge and diverge but lack the stamina to maintain alignment comfortably. Patients often report eye strain, fluctuating clarity, or discomfort despite normal alignment at rest.

How Visual Issues Affect Beery VMI Performance

A child with poor eye tracking, unstable fixation, or reduced visual-motor coordination may:

• Misjudge angles, spacing, or proportions of shapes
• Start drawings in the wrong place or drift off the lines
• Produce uneven or shaky lines
• Tire quickly or lose focus mid-task
• Show inconsistent accuracy between simple and complex figures
   

As an aside, many parents ask how vision can affect handwriting. Handwriting is a complex skill, involving fine motor coordination, spatial awareness, and visual-motor integration. From a developmental and functional optometry perspective, handwriting represents a motor output based on visual sensory input—if the information entering the visual system is inaccurate or inefficient, the written output will reflect that. As my mentor from SUNY College of Optometry, Dr. Rochelle Mozlin, used to say: “Garbage in, garbage out.”
 

TVPS-4 (Test of Visual-Perceptual Skills)

The last test we will highlight is the TVPS-4.  This is a common test used by psychologists and developmental optometrists to assess how visual processing impacts performance, and can provide useful clues about underlying visual inefficiencies.
 

This is an example of a visual discrimination test part of the TVPS-4 test.

 

This is how a child with central peripheral vision integration issues see. 

 

Central–peripheral integration refers to the brain’s ability to balance and coordinate focused central vision (used for detail and attention) with broad peripheral vision (used for spatial awareness and stability). When this system is imbalanced—often seen in individuals with autonomic nervous system dysregulation involving the sympathetic and parasympathetic systems—the visual system can become unstable. Patients may describe sensations of the world “zooming in or out,” feeling as though they are looking through a fishbowl, or that their surroundings appear compressed or expanded. This reflects a disruption in how the brain integrates visual information for orientation and depth perception. Instead of fluidly shifting between detailed focus and spatial awareness, the system oscillates or locks into one mode, leading to discomfort, disorientation, and visual distortion. Vision therapy in such cases aims to retrain the visual system’s balance between central and peripheral processing to restore a sense of visual stability and spatial grounding.
 

In summary, Imagine trying to solve a puzzle or read a passage while the image is unstable—moving, blurring, or doubling. Now imagine being timed while doing it. That’s the reality for many children with binocular vision dysfunction or visual processing issues. These children often show unexpected drops in performance, especially in timed tasks, multi-step instructions, or tasks that rely on copying or scanning.
 

It’s not that they don’t understand the material—it’s that the information isn’t being delivered to their brain in a usable way.
 

This distinction matters. A child’s testing results influence educational planning, diagnosis, and intervention decisions. If their visual system is not functioning efficiently, their scores may lead to incorrect labels or missed diagnoses. Worse, they may internalize these results as a reflection of their ability, when in fact their brain is working overtime to compensate for an unstable visual experience.

 

When to Suspect a Visual Efficiency Problem

Psychoeducational results sometimes don’t align with the child’s classroom performance. When scores raise more questions than answers, visual efficiency should be on the radar. Consider referring for a functional vision evaluation if you observe:

• A significant discrepancy between Verbal Comprehension and Processing Speed Index on the WISC-V

• A normal Visual Perception score but a low Visual-Motor Integration score on the Beery VMI

• Observations or complaints such as:

  • Headaches or eye strain during reading or homework

  • Words that blur, double, or appear to move on the page

  • Frequent line skipping, losing place, or finger tracking

  • Tilting the head or covering one eye while reading or copying

Visual Symptoms That Mimic Other Diagnoses
Many visual efficiency issues look like learning or attention disorders. These are some of the most common overlaps:

• ADHD vs. Oculomotor Dysfunction: Visual tracking problems can reduce attention during reading tasks

• Dysgraphia vs. Visual-Motor Delay: Poor handwriting may stem from eye-hand coordination deficits

• Processing Speed Deficit vs. Accommodative Dysfunction: Visual focusing lag can slow down timed tasks

Identifying the correct source of the issue can prevent misdiagnosis and ensure the child receives targeted support.
 

Quick Screening Tools for Psychologists

You don’t need to diagnose visual problems to refer a child appropriately. These quick, in-office screens can help determine when further evaluation is needed:

• Near Point of Convergence (NPC): Slowly move a pen or target toward the child’s nose. A normal response is single, clear vision until 2–3 inches away. Earlier blur, double vision, or drifting of one eye indicates potential convergence insufficiency.

• Symptom Checklists: Brief tools like the CISS (Convergence Insufficiency Symptom Survey) can flag visual fatigue, discomfort, or avoidance of near work.

• Oculomotor Screening Tools: Simple tests like the King-Devick or Developmental Eye Movement (DEM) Test can reveal tracking deficits. These assess saccadic eye movements during rapid number naming tasks and can help identify children struggling with visual attention or reading fluency.

 

What’s Next: Assess the System Before Measuring Performance

When conducting psychoeducational testing, it’s essential to consider how underlying visual factors may influence performance. This begins with evaluating—and when appropriate, addressing—visual efficiency and visual- processing. A comprehensive functional vision evaluation can uncover key areas of difficulty, including:

• Tracking and saccadic eye movements
• Eye teaming and convergence
• Focusing (accommodation)
• Visual-motor coordination
• Spatial awareness and visual memory
   

Addressing these deficits through vision therapy or appropriate interventions can help level the playing field, ensuring that psychological testing measures true cognitive function—not the side effects of a struggling visual system.
 

At Miami Vision Therapy, we work closely with families and psychologists to provide this missing piece. Our evaluations and therapy programs support children in reaching their full potential—because performance should reflect ability, not undetected visual strain.