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Ocular Motor Complications & Their Impact on the Reading Process Marva Gellhaus, PhD SD School for the Blind & VI July 24, 2010 AER International Conference.

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Presentation on theme: "Ocular Motor Complications & Their Impact on the Reading Process Marva Gellhaus, PhD SD School for the Blind & VI July 24, 2010 AER International Conference."— Presentation transcript:

1 Ocular Motor Complications & Their Impact on the Reading Process Marva Gellhaus, PhD SD School for the Blind & VI July 24, 2010 AER International Conference Little Rock, Arkansas

2 Objectives Define fixation, smooth pursuits & saccadic eye movements & explain their importance to reading fluency Explain the impact of ocular motor difficulties on reading fluency for student’s with low vision Explain why increasing a student’s span of recognition & tapping into a student’s long term memory are effective methodologies

3 Who observes and documents ocular motor skills? Eye care specialists? Addressed in reports Not specific to reading process (Medically based) Parents? LD Teachers? Vision teachers? Reading Teachers? Classroom teachers? Occupational therapists? Does anyone synthesize the ocular motor and reading process information?

4 Ocular motor stress symptoms Intermittent blurred vision Diplopia Visual fatigue Orbital aching Eyes burning Headaches

5 Eye Muscle Expectations Fixation-hold the image on the fovea Vestibulo-ocular reflex-hold the image steady during brief head rotations Optokinetic-hold the images steady during sustained head rotations & gaze shifting Smooth pursuits-hold the images of moving target on the fovea Saccades-holds images of eccentrically located objects of interest on the fovea Vergences-images of both eyes “fuse” into one image

6 Fixation Hold the central image of a stationary object on the fovea Pauses to take in information First grader pauses 224 times per 100 words College student pauses 90 times per 100 words

7 Vestibulo-ocular reflex Hold the images of the seen world steady on the retina during brief head rotations This may be abnormal with some brain stem defects

8 Optokinetic Hold images of the seen world steady on the retina during sustained and low frequency head rotation and gaze shifting

9 Smooth pursuits Hold the image of a moving target on the fovea Symptoms (difficulties noted) Jerking eye movements/midline tremors Excessive head movements while reading Poor performance in sports Movements are in one direction

10 Saccades Directs images of eccentrically located objects of interest on the fovea Movements in more than one direction Quick movements of both eyes in same direction Mechanism for fixation, re-fixation, rapid eye movement

11 Saccades-Difficulties Noted Head movements Frequent loss of place Omission of words Skipping lines Slow reading speed Poor comprehension Difficulty with columns of numbers Difficulty copying

12 Saccades-Difficulties Noted Letters compete for space near fovea; results in visual crowding Visual crowding observations tools Near Reading Card for the Partially Sighted LEA Cards Other Cards Educator created cards for screenings

13 Saccadic Eye Movements and Reading Muscle controlled saccadic eye movements Linked to and affect span of visual recognition (amount of visual information formed on the fovea in a given fixation) Good saccades-10 eye movements per line Poor saccades-dramatic increase in eye movements (Back tracking necessary to pick up lost or unperceived information)

14 Saccadic Eye Movements & Reading Span of fixation reduced when eye muscle complication exist Each fixation must be remembered in sequence to put a line together Multiple visual fixations have multiple auditory (phonetic) components Reduced span of recognition and uncontrollable eye movements make process of reading significantly more complex

15 Vergence Moves the eye movements so that images of a single object are placed simultaneously on the foveae of both eyes and the image fuse to send one image back to the brain

16 Main concerns for reading Fixation Smooth pursuits Saccades Vergence Sole purpose of the ocular motor system is to keep the image we are looking at on both foveae at the same time

17 Observations by Evaluator Have child track object: move object horizontally, vertically, and diagonally Do eyes move smoothly together, horizontally, vertically and diagonally? Have child watch your finger move toward his/her nose Do eyes move smoothly inward as object is moved towards nose?

18 Next Step-Documentation of Eye Condition Existing eye care specialist’s reports can be examined to determine current documentation from eye care specialists Observation and inquiries should be recorded for further investigation and documentation by eye care specialists

19 Teaching Reading? Now What? Learn implication of weak/poor eye movements on the reading process (DONE!) Move information from short to long term memory Increase a student’s span of recognition

20 Memory & Reading 1 Input into sensory store is affected by acuity, span of visual recognition, number of fixations, visual field, magnification--- Visual input and information from long and short memory store are integrated to create reading comprehension

21 Long Term Memory & Reading Reading (decoding) and comprehension are heavily dependent on information retrieved from long term memory. The more information that is stored in long term memory, the less processing (use of visual and auditory memory and sequencing) that is needed for reading.

22 Long Term Memory & Reading Sight words are stored in long term memory and quickly retrieved. Experience and concepts are stored in long term memory.

23 How Can We Improve Reading Fluency? We must increase a student’s span of recognition.

24 Increasing Span of Recognition 1 Display for 1 second Series of letter Meaningful clusters (grouping and chunking of words and whole words) Add context (meaningful sentence) The more information we have in long term memory, the less processing we have to do.

25 Increasing Span of Recognition 2 Span of recognition can be increased by chunking or grouping letters together in a single meaningful symbol. Phonetic approach-requires sequencing of four sounds (b-r-o-k-e) Chunking approach-requires sequencing of two sounds (br-oke): visual & auditory sequencing greatly reduced

26 Learning Chunks (Prerequisite skills) Identify rhyming sounds auditorily Identify sounds of all consonants used in the lesson Know sight word of one of one member of the word family

27 Chunks-Increasing Span of Recognition Practice with chunks; repetition of chunks (initial sound with chunks) (Knowledge of phonics is necessary, but this process is simplified by learning one syllable sound/spelling patterns known a chunks)

28 Chunks-Word Families Word families, sound families, phonograms or rhymes are consistent one syllable sound/spelling patterns found in a series of words 500 primary grade words can be derived from 37 high frequency word families.

29 Learning Word Families 500 primary grade words are derived from the 37 high-frequency words word families listed below -ack –ail –ain –ake –ale -ame –an –ank -ap –ash –at –ate –aw –ay –eat –ell -est –ice –ick –ide –ight –ill –in –ine -ing –ink –ip –id –ock –oke –op –ore –ot -uck –ug –ump -unk

30 When you get home--- Observe and document student’s eye movements Help student place information in long term memory Increase student’s span of recognition by using the “Chunk Method” Teach word families Practice, practice

31 Bibliography Developing Ocular Motor and Visual Perception Skills by Kenneth Lane Dr. Dorothy Perkins-Professor of Reading Psychophysics of Reading in Normal and Low Vision by Gordon E. Legge The Reading Teacher’s Book of Lists by E. B. Fry, J. K. Polk, and D. Fountoukidis Marva’s Website:


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