What is dyslexia?

Mark Eagle, Behavioural Optometrist, can share a lot of understanding about Learning-Related Visual Disabilities with you.

Reading is a highly Visual task performed by the brain.

If the brain has not developed in a conventional way, or has been injured through concussion or stroke, eye control and reading function can be impaired.

When speaking of vision, we are not referring to just whether the person can read the little letters on the eye chart – we are talking of the higher-level neurological processing of a mass of coded squiggles of ink into meaningful comprehension, and on to meaningful communication.

Reading is partly about the creation of visual imagery to direct the reader to a particular view of the world or action in the world.

Some experts postulate that reading is an auditory dominant process and they centre on Phonics and Phonetic training. This position is not supported by the fact that we do not expect people to read with their eyes shut.

Reading is a very fast, visually-driven task; the retinal image needs to be seen as stable, decoded quickly, accurately processed through the visual pathways and tested against visual memory. If there is not enough speed and accuracy in the information processing pathways, phonic attack skills will struggle to compensate for the visual deficit; Fluency is obstructed.

Reading is a visual language-based function.

The term Dyslexia is used when there is a significant weakness in the neurological processes required for reading, given normal intelligence and learning opportunity. This typically relates to the persons ability to read or write 'whole words' - there is not time to phonetically attack letters and blends with sufficient speed to maintian fluency and comprehension.

If, however, a person has poor control of their eye movements, poor visual perception, poor visual acuity or poor binocularity, they are unlikely to have had a fair educational opportunity to learn to visually read.

Here is the definition of Dyslexia that I have found to be simple, meaningful and relevant to the children that I see:

Dyslexia is when there is something strangely wrong with reading, writing or spelling despite the person having the intelligence and having had the educational opportunity to do better.

Has your child had a fair visual opportunity to read?

Young girl with hand in a heart shape around eye

Vision, in the broadest neurological sense, is the common thread to the sensory issues involved in reading laid out below.

Learning Related Visual Disabilities (LRVD)

  • Dyseidesia form of Dyslexia (Visual Dyslexia) (a weakness in flash-known word recognition of seen words)
  • Irlen Syndrome (Visual Stress)
  • Dyscalculia

Learning Related Auditory Disabilities (LRAD)

  • Dysphonesia form of Dyslexia (Auditory Dyslexia) (a weakness in flash-known sound recognition of seen words)
  • Phonologic deficits

Learning Related Auditory-Visual Disabilities (LRAVD)

  • Dysphoneidesia form of Dyslexia (Auditory-Visual Dyslexia) (a weakness in both the flash-known sound recognition of seen words and the flash-known word recognition)
  • Phonologic deficits

Learning Related Cerebellar Disabilities (LRCD)

If a person has a weakness for Information processing, it can often be remediated by using the dominant sensory channel of Vision.

This is what we do with Optometric Vision Therapy.

Book an appointment with Mark Eagle to investigate this further.

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