Assessment of Eye Movements - Clinical Binocular Vision Fall 2026

What is the length of an avg saccade?

-8-9 character spaces (2º)

-200-250ms on avg

What is the typical % of time spend on regressions in a skilled reader?

10-20%

What are the common symptoms of oculomotor dysfunction?

-Difficulty reading

-Frequent loss of place when reading

-Skipping words or lines

-Slow reading speed

-Decreased comprehension and attenuation when reading

-Difficulty copying from the board

-Difficulty solving math problems in columns of numbers

-Difficulty taking tests with computer scan sheets

-Poor sports performance

What are the signs of oculomotor dysfunction?

-Increased saccades and regressions

-Excessive head movements when reading

-Inaccurate fixations, saccades & pursuits

-Below age expected test performance

What are important DDx of oculomotor dysfunction?

-Pathological causes of eye movement dysfunction

-Medications that affect eye movement function

How to assess stability of eye fixation?

Observation of fixation for 10" with CT or eye movement testing

How to assess saccadic eye movements?

-Subjective observation with NSUCO

-Visual-verbal timed, standardized tests

-Electro-Oculographic Instruments

-Pepper Visual Skills Reading Test

-OKN

What are the subjective observation tests to assess saccadic eye movements?

NSUCO

What are the visual-verbal timed, standardized tests to assess saccadic eye movements?

Developmental Eye Movement test (DEM), King-Devick (KD)

When would you do an OKN test to assess saccadic eye movement?

with suspected pathology

How to assess pursuit eye movements?

With subjective observation

Who can the NSUCO test for subjective observation of saccades be performed on?

5yo to adults

How to perform the NSUCO test for subjective observation of saccades?

-Patient is binocular

-Patient stands in front of the examiner w/ feet shoulder width apart

-Patient looks back and forth between the 2 targets 20cm apart (Centered at the midline)

-Patient will repeat 10 times (5 round trips across the horizontal meridian)

What is the test distance for NSUCO test for subjective observation of saccades?

Harmon distance for kids, 40cm for adults

How to score the NSUCO test for subjective observation of saccades?

-Rate performance on a scale from 1-5

-Rate ability

-Rate Accuracy -- corrections or refixations present?

-Quantify Head movement (>50%,

True or False:

The technique of NSUCO is easy to learn but observations may be difficult to master

true

What are the downsides to the NSUCO test?

-Interobserver and Intraobserver reliability and repeatability problems

-Difficult to quantify results

What is NSUCO results useful for?

-For dx of oculomotor dysfunction

-To measure progress during therapy

What do the visual-verbal timed, standardized tests measure?

eye movements used in reading

What is the goal of the DEM (KD) test for assessment of oculomotor dysfunction?

Name numbers as quickly as possible (no finger should be used)

What are the DEM (KD) tests for assessment of oculomotor dysfunction useful for?

-Dx of coulomotor dysfunction

-Measure progress during therapy

How to perform DEM Saccadic Eye Movement testing?

-Tests A, B and C

-Test vertical time

-Test horizontal time

-Takes the ratio of vertical/horizontal time

-Calculate errors

-Compare performance to expecteds

Is there repeatability issues with DEM testing?

Yes

What is the King Devick test used for?

-Reading

-Compare performance to expected values

-Can be used for concussion screening

How to use King Devick testing for concussion testing?

-Baseline (test every 6mo for kids

How to assess saccadic eye movements with objective eye movement readings?

-Electro-oculographic instruments

-Visgraph

-Readalyzer

-Eye Trac

-RightEye

What is the benefit of using objective eye movement readings to assess saccadic eye movements?

Quantitative (Number of fixations, regressions, duration of fixations, reading rate)

True or False:

Objective eye movement readings are normalized

true

How to perform objective eye movement readings?

-Find appropriate reading level (

Visagraph Print Out (Pic)

Visagraph Print Out (Pic)

ReadAlyzer Print Out (Pic)

ReadAlyzer Print Out (Pic)

ReadAlyzer Print Out -- Eye Tracking (Pic)

ReadAlyzer Print Out -- Eye Tracking (Pic)

ReadAlyzer Passages (Pic)

ReadAlyzer Passages (Pic)

What is the visagraph used for?

Applications for dx and monitoring improvements w/ therapy

What is the limit of agreement fixations that are used to score Visagraph results?

60

**Higher number than this would be concerning

How to subjectively assess pursuit eye movements?

Patient will follow a moving target in a broad H pattern and then in a circular motion. Both binocular and monocular.

How to grade subjective assessment of pursuit eye movements?

-4 + = smooth and accurate

-3 + = one fixation loss

-2 + = two fixation losses

-1+ = more than two fixation losses

What is the expected value for subjective pursuit eye movement testing?

3+ or better

You can subjectively observe pursuit eye movements with what test?

NSUCO Oculomotor test

How to perform NSUCO oculomotor test to observe pursuit eye movements?

-Rotate the bead in ~20cm diameter circle, centered at midline

-2 rotations clockwise, 2 rotations counterclockwise

What are the downsides to the NSUCO oculomotor test to observe pursuit eye movements?

difficult to quantify results

What is the NSUCO oculomotor test to observe pursuit eye movements used for?

-Diagnosis of oculomotor dysfunction

-Measure progress during therapy

_____% of patients who were untreated after a failed DEM test failed again 1+ years later when retested

72

What is the goal of oculomotor dysfunction management?

-Normalize ocular motor function and eliminate symptoms

-Effect on reading and sports performance is undetermined

How to manage oculomotor dysfunction?

-Prescribe for uncorrected RE

-Therapy for isolated oculomotor dysfunction

True or False:

You need adequate acuity for accurate EMs

true

There is been shown to be increased reading scores with _____ sessions of computer based therapy

20-30

Can oculomotor dysfunction be related to other accommodative or binocular problems?

Yes