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
ELEMENT | PERFORMANCE CRITERIA |
Elements define the essential outcomes | Performance criteria describe the performance needed to demonstrate achievement of the element. |
1. Evaluate client needs | 1.1 Interpret the parameters of atypical prescriptions and transpose as required 1.2 Analyse the prescription and identify areas of freedom and constraints 1.3 Assess the individual needs and requirements of the client 1.4 Select possible frame, lens and treatment combinations to suit individual requirements based on principles of low vision aid selection, depending on client’s needs |
2. Determine specifications for atypical prescriptions | 2.1 Take accurate measurements and make calculations necessary to accurately dispense atypical prescriptions 2.2 Select option that best meets cosmetic, optical and functional needs 2.3 Determine the correct working distance for low vision aids |
3. Fit frames and lenses for atypical prescriptions | 3.1 Organise required fitting equipment and materials 3.2 Select and specify appropriate bevelling and edging requirements to enhance the cosmetics and quality of the spectacles 3.3 Select appropriate lens treatments or additional requirements to maximise the visual performance and enhance the quality of the finished spectacles 3.4 Measure and specify the most appropriate lens fitting criteria 3.5 Ensure the quality of the finished spectacles 3.6 Fit and adjust the spectacles to client needs |
4. Instruct client on wear and care | 4.1 Provide client with details about how to wear the appliance 4.2 Offer information about appliance care routines 4.3 Reinforce and support advice provided by low vision practitioner on correct use of low-vision aids |
5. Finalise dispensing process | 5.1 Complete financial transactions in accordance with relevant policies and procedures 5.2 Follow correct procedures for client rebates 5.3 Complete and store records in accordance with relevant policies, procedures and confidentiality requirements 5.4 Offer follow up services in accordance with organisation procedures |
Evidence of Performance
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
Evidence of Knowledge
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.
Foundation Skills
The Foundation Skills describe those required skills (language, literacy, numeracy and employment skills) that are essential to performance. |
Foundation skills essential to performance are explicit in the performance criteria of this unit of competency. |