Tuesday 19 March 2013

Theory and practice. Applying visual processing ideas in a primary School


Theory and practice. Applying visual processing ideas in a primary School

Today, my colleague and I begin a short longitudinal study with a UK Primary school.

Background
All of the pupils at this school will have followed assiduously the UK government Phonics programme for the last five years.  

This study will consider what might happen if visual processing is added to the provision.

The use of binocular eyetracking technology will allow the consideration of visual span/perceptual span as a contributor to reading fluency and the quantification of benefit from optometric /orthoptic intervention and visual parameter intervention (font size and text background).

The outcomes will be considered in terms of the role of visual crowding in reading performance.

Other posts in this blog look at these issues in adults.

Method
Screen all Year 6 with CRST test ( a comparative rate of reading test) to indicate eye tracking and visual crowding problems, and a computerized Oral Fluency Reading (ORF) test, age suited, to attain words per minute reading speed. Combining the results we will attain a percentile rank of each child in class, which can be compared to school assessed reading levels.

Both these tests can be undertaken in school by a Learning Assistant.  Each test takes approx. 1 minute to perform
Select the bottom 20th percentile, plus any other students who have not been captured in this group but who the school feel would benefit from further investigation. (A maximum of 9 students for logistical purposes)

Treatment

For the bottom 20% group in rank order and those identified as outlined above.
We will run clinic with parents attending if poss. to perform following:
Stage 1. Optometric assessment
·        Assess accommodation ability with RAF rule, dynamic retinoscopy, near duochrome, and +1.00 binocular add test
·        Assess convergence , near muscle balance and AC ratio using RAF rule and Maddox wing
·        Check for fixation disparity with any reading add found using near mallet unit. Determine prism as indicated, then check stereopsis and suppression.
·        Prescribe and dispense any reading specific glasses initially clear.

The above testing will take approx. 30 mins per student

Stage 2 Optometric provision

In the test group any spectacles required will be provided and worn for the following tests.
·        Re-measure CRST and ORF with specs if required
·        Initial eye tracking plot on default font/size and white screen.

Stage 3 Computer screen optimisation

·        Optimize font size
·        Optimize colour and luminance
·        Repeat eye tracking with best colour and font.

Stage 4 provision of provision tinted glasses

·        Return any prescription spectacles to lab for precision tinting or dispense plano spectacles with the precision tint found.
·        Supply tinted specs to child,  retest whole class CRST and ORF in school by Learning Assistant
·        Recalculate and compare percentile class ranking to the original
·        A second pair of spectacles with 50% reduced power and incorrect tint will be dispensed to all selected students, and CRST and ORF results compared. The Learning Assistant will not be told which the correct specs were; this would act as a double blind placebo test.

Stage 5 Longitudinal study

Return after 1 month for
  1. teacher assessment of any reading change,
  2. Eye tracking plot all pupils in group.
  3. CRST   all pupils
  4.  ORF all pupils

After 6 months

Follow up 6 month an optometric assessment of all in test group.













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