Unit of competency

Modification History

Application

This unit describes the skills and knowledge required to evaluate client needs, take measurements and make calculations to facilitate effective dispensing for atypical prescriptions, including for low vision clients. Low vision occurs when, after accurate refraction and the provision of spectacles or contact lenses to correct the refractive error, good visual acuity is not achievable.

This unit applies to optical dispensers who work according to prescriptions provided by optometrists or ophthalmologists.

The skills in this unit must be applied in accordance with Commonwealth and State/Territory legislation, Australian/New Zealand standards and industry codes of practice.

Elements and Performance Criteria

Foundation Skills

Unit Mapping Information

No equivalent unit.

Links

Companion Volume implementation guides are found in VETNet - https://vetnet.gov.au/Pages/TrainingDocs.aspx?q=ced1390f-48d9-4ab0-bd50-b015e5485705

Assessment requirements

Modification History

Performance Evidence

The candidate must show evidence of the ability to complete tasks outlined in elements and performance criteria of this unit, manage tasks and manage contingencies in the context of the job role. There must be evidence that the candidate has:

• dispensed optical appliances in response to at least 5 different atypical prescription needs
• determined the criteria for atypical dispensing, including making accurate calculations for the following:

• change in vertex distance
• compensated power (Fc)
• effective power (Fe)
• effectivity
• prescriptions requiring compensations

• calculated differential prismatic effect and compensation using different sized segments, Fresnel prisms, or slab off bifocals
• calculated field of view and determine ways to improve the field of view
• calculated spectacle magnification and determine ways to reduce the effects of aniseikonia
• compounded and resolved prism

Knowledge Evidence

The candidate must be able to demonstrate essential knowledge required to effectively complete tasks outlined in elements and performance criteria of this unit, manage tasks and manage contingencies in the context of the work role. This includes knowledge of:

• legal and ethical considerations for dispensing optical advice to clients:

• duty of care
• informed consent
• privacy, confidentiality and disclosure
• records management
• work role boundaries – responsibilities and limitations
• work health and safety

• requirements of dispensing spectacles to clients with special or complex needs, including:

• low vision, what it is, and how various aids may be used to assist such clients

• types of atypical prescriptions, how to interpret and transpose them, including:

• anisometropia
• aphakia
• high ametropia
• prism

• features and capabilities of aphakic lenses including:

• aspheric lens design
• centering
• compensating for vertex distance change
• edging/bevelling profile
• full field lens design
• general problems associated with dispensing aphakic lenses including jack-in-the-box effect and ring scotoma
• lenticular designs

• field of view and its impact on atypical dispensing, including:

• apparent versus real
• aspheric lenses
• calculations
• high minus corrections
• high plus corrections

• features of high ametropia including:

• back vertex power (F’v) front vertex power (Fv)
• compensated surface power
• corrections
• prescription requirements and constraints
• thick lens power
• types

• high minus lenses and negative lenticulars and how they are used, including:

• centering
• compensating for vertex distance change
• dispensing high index materials
• edging/bevelling profile
• high index materials
• lenticular types and designs
• surface reflections and the need for anti-reflection and multi-coatings

• high prismatic corrections and how they are achieved, including:

• edging/bevelling profile
• fresnels and their use
• high horizontal prism
• high vertical prism

• ways to respond to aniso and antimetropia including:

• base curve selection
• correcting vertical imbalance problems
• effects of lens form (shape)
• effects of thickness
• prism differential

• features of spectacle magnification including:

• effects on visual acuity
• positive compared to negative lenses
• retinal image size

Assessment Conditions

Skills must have been demonstrated in the workplace or in a simulated environment that reflects workplace conditions. The following conditions must be met for this unit:

• use of suitable facilities, equipment and resources, including:

• vertex distance calculator (disc or table/chart)
• vertex distance rule
• vertex distance calliper (distometer type)
• lens measure
• pupillary distance (PD) rule
• pupillometer
• thickness callipers

• modelling of industry operating conditions, including integration of problem solving activities

Assessors must satisfy the Standards for Registered Training Organisations (RTOs) 2015/AQTF mandatory competency requirements for assessors.

Links

Companion Volume implementation guides are found in VETNet - https://vetnet.gov.au/Pages/TrainingDocs.aspx?q=ced1390f-48d9-4ab0-bd50-b015e5485705