Dr Grant Hannaford

Dr Grant Hannaford is an adjunct lecturer at the School of Optometry and Vision Science University of New South Wales and the Save Sight Institute University of Sydney. He co-owns two time Australian Small Business Champion independent optometry practice Hannaford Eyewear and the Academy of Advanced Ophthalmic Optics. Dr Hannaford holds a qualification in spectacle lens design with honours from the UK under the tutelage of Professor Mo Jalie and is a fellow of the Association of British Dispensing Opticians. He is a Rotary Paul Harris Fellow and is formally recognised by the Australian government for his charitable works in Mongolia and Nepal. Dr Hannaford was the Silmo and the International Opticians Association’s 2022 International Optician of the Year and now researches ocular biometric development in children and lens design after having completed his doctoral candidacy at the School of Life and Health Sciences at Aston University, Birmingham England.

 

Grant presents:

Friday 11 September 9:15am

Why patients reject their glasses: Optical and Neurovisual Mechanisms of Adaptation – 1 General GenDO

Non-tolerance to newly dispensed spectacles remains one of the most common and challenging presentations in clinical dispensing practice. While frequently attributed to patient factors or “adaptation issues”, many such presentations arise from predictable optical and binocular consequences of modifying the refractive state of a coupled lens/eye system.  This lecture examines adaptation and rejection of refractive correction through the framework of applied ophthalmic optics. Alterations in sphere, cylinder and axis introduce changes not only in foveal refractive state, but also in magnification, prismatic demand, skew distortion, peripheral astigmatism and binocular vergence balance. These effects are further influenced by vertex distance, pantoscopic tilt, wrap angle, progressive corridor geometry and object distance.

Drawing on contemporary modelling approaches and clinical case examples, the session will explore:

• The spectacle lens/eye system as a coupled optical instrument

• Magnification and finite object distance effects in near vision

• Prismatic imbalance and adaptation in progressive addition lenses

• Skew distortion and oblique astigmatism in real world wear

• Neural adaptation versus optical intolerance

• A structured troubleshooting framework for clinical practice

The objective is not merely to describe adaptation, but to enable prediction. Delegates will leave with a systematic approach to analysing non-tolerance presentations and managing them confidently within everyday practice. This session directly addresses troubleshooting in dispensing practice and provides a clinically applicable framework for reducing remakes, improving patient satisfaction, and enhancing professional confidence in complex prescriptions.

Learning Outcomes

Participants will be able to:

1 Describe the optical mechanisms contributing to non-tolerance of refractive correction.

2 Explain the influence of magnification, prism and peripheral aberration on binocular comfort.

3 Identify when neural adaptation is likely to occur and when optical modification is required.

4 Apply a structured troubleshooting framework to real clinical dispensing scenarios.

 

Saturday 12 September 8:30am (Workshop Carlton 1)

TROUBLE-SHOOTING NON-TOLERANCE: A STRUCTURED OPTICAL APPROACH TO CLINICAL CASES – 1 GenDO

Non-tolerance complaints are frequently approached reactively; however, many arise from quantifiable and predictable optical changes introduced by the prescribed correction. This interactive workshop develops a structured method for analysing and managing such cases using applied ophthalmic optics.

Through guided case studies, participants will examine scenarios including:

• Significant cylinder axis change

• Anisometropic magnification imbalance

• Progressive addition lens discomfort at near

• Distortion in wrapped or sport frames

Each case will be analysed using fundamental principles including Prentice’s rule, shape and power factor magnification, oblique astigmatism considerations and prism/cylinder interactions. Practical website calculator-based modelling tools will be demonstrated to illustrate how small prescription changes can produce disproportionate perceptual effects.

The emphasis is on translating optical theory into chairside reasoning. By the end of the workshop, participants will be able to systematically evaluate the likely source of intolerance and determine whether adaptation, prescription modification or lens redesign is indicated.

Learning Outcomes

Participants will be able to:

1 Apply fundamental optical principles to analyse non-tolerance complaints.

2 Quantify prismatic and magnification changes resulting from prescription modification.

3 Differentiate between binocular adaptation phenomena and optical design limitations.

4 Formulate evidence-based solutions to reduce remake frequency.

 

Saturday 12 September 11:00am (Workshop Lombard – limit 30 attendees)

PRISM SKEW AND DISTORTION: UNDERSTANDING THE HIDDEN OPTICS BEHIND SPECTACLE ADAPTATION – 1 General GenDO

Spectacle lenses function under conditions far removed from the assumptions of paraxial optics. Oblique incidence, frame tilt, wrap geometry and progressive surface design introduce distortion, prismatic effects and peripheral astigmatism that may significantly influence wearer comfort.

This workshop explores the less visible optical contributors to adaptation difficulties, including:

• Skew distortion arising from oblique astigmatic correction

• Peripheral astigmatism and Minkwitz-related design constraints in progressive lenses

• Prismatic imbalance at near and its interaction with binocular vision

• The relationship between vertex distance modification and effective far-point sphere

Participants will engage with visual demonstrations and simplified modelling tools to appreciate how seemingly minor prescription or fitting parameter changes alter retinal image geometry. Particular attention will be paid to the interaction between prism and induced cylindrical error, and the limits imposed by lens surface design.

The session aims to bridge advanced optical concepts with practical dispensing insight, enabling practitioners to anticipate distortion-related intolerance before lenses are dispensed.

Learning Outcomes

Participants will be able to:

1 Describe the origin of skew distortion and peripheral astigmatism in spectacle lenses.

2 Explain the interaction between prism and induced cylindrical effects.

3 Evaluate how frame and fitting parameters influence retinal image geometry.

4 Apply preventative strategies to minimise distortion-related intolerance.