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VisionLink Behavioural Optometrists provide research based treatment for convergence insufficiency, oculomotor dysfunction, spelling and reading problems, dyslexia, attention deficit disorders, Aspergers, Learning Related Vision Disabilities, migraine and brain injuries. We are uniquely positioned to assist Visual Perception through the use of Vision Therapy, Irlen tinted lenses and Cellfield Intervention.

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Speech given about the many uses of Yoked Prism lenses

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Mark Eagle

Mark Eagle from VisionLink gave a well-received speech on this fascinating topic at the recent Annual Symposium of the local branch of Physiotherapy NZ in Hawkes Bay for allied health professionals at the Education Centre, Hastings Hospital.

The Symposium theme was Dynamic Wellness:  Embracing the Four Pillars of Health with an emphasis on mental health and the management of chronic pain. Attending were physiotherapists, osteopaths and podiatrists.
Keynote speaker was Warren Bernard, a clinical psychologist in the cancer, renal and chronic pain service at the HBDHB.

Aspects covered by Mark in his presentation included;

  • Models of Vision;
  • The eye as an end organ    
  • Eyesight 20/20   
  • The Extra-Ocular muscles  
  • Passive Vision    
  • Central vs Peripheral       
  • Seeing objects          
  • Observing detail        
  • Language; speech reading & writing
  • Living the visual dream   
  • Spectacles and Vision Therapy 
  • What are the tools of a Behavioural Optometrist;
    • Therapeutic lenses; Prism lenses, Plus lenses, Minus lenses, Tinted lenses
    • Body Exercises, Eye Exercises, Cognitive Exercises
  • Prism lenses and what they do to our perception of space
  • Yoked Prisms; A binocular strategy that modifies Visual / Vestibular integration/ Posture
  • They can alleviate the symptoms of;
    Asthenopia, Inefficient vision, Poor saccadic eye movements, nystagmus, Reduced accommodation response, Errors of spatial judgment, Poor peripheral awareness, Nausea, dizziness, motion sickness and Fatigue.
  • Clinical application of Yoked Prisms to;
    Oculomotor Dysfunction, Esophoria, Exophoria, Strabismus, Duanes Syndrome, Adaptive head posture, Nystagmus and Saccadic eyemovements.
  • Acquired Brain Injury; Trauma / Stroke / Hemiparesis / Hemiplegia / Post-Concussion Vision Syndrome / Visual Midline Shift Syndrome / Visual Field Loss / Hemi field Neglect
  • Postural problems; Scoliosis / Cerebral palsy / Gait / Chronic Fatigue Syndrome / Agarophobia / Autism (Posture and attentiveness) / Schizophrenia (Saccades) / Relief for Pathologic Pain (midline shift)
  • Methods of Assessment for the prescribing of Yoked Prisms


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