Course description
This course provides students with the laboratory skills for quality control of lenses and the ability to layout and prepare lenses for edging. Students will learn how to maintain the equipment and tools associated with the edging and finishing laboratory. It provides the student with skills to insert and mount lenses into various frame
materials and designs.
Course content
- Introduction
- course content and requirements
- orientation of the equipment and tools
- an overview of the edging process
- introduction to industry standard charts
- safety procedures in the laboratory
- Spotting of Lenses
- checking for optimal surface quality
- use of the lensometer
- power verification of single vision lenses
- optical centre versus major reference point
- single vision lenses with prism
- Frames
- frame parts, types & materials
- frame measurements & markings
- frame selection
- frame alignment & adjustment
- frame repairs
- specialized frames
- lens insertion
- frame maintenance & cleaning
- Centration of Single Vision Lenses
- the mechanics of lens centration
- horizontal and vertical centration
- the boxing system
- calculating lens blank sizes
- industry standards formulas
- Blocking of Lenses
- the lens protractor
- marking a single vision lens
- double checking lens blank size
- pupil distances and accuracy
- blocking systems and their relationship to lens materials
- deblocking lenses
- Lens Shape Formation
- pattern measurements and terminology
- mounting and datum lines
- pattern formation
- Edging
- the edging process
- deviations from edger settings
- lens chucking
- bevel selection
- verification with polariscope
- variations in lens materials
- Hand Edging
- purpose of hand edging
- developing the correct technique
- correctional modifications
- edge polishing
- Lens Insertion and Mounting
- frame materials
- mounting design variations
- hand tooling
- heating and cooling
- drilling and notching
- grooving and nylor mounts
- lens alignment
- frame alignment
- securing screws and pins
- final verification
- Identification of Lens Types, Materials and Coatings
- Equipment Maintenance
- basic equipment maintenance
Learning activities
- Laboratory Lectures
- Application / Calculation exercises in Laboratory
- Independent Study of Courseware
- Completion of Proficiency Tests
- Completion of Laboratory Assignments
- Online discussion forum
Means of assessment
The course evaluation is consistent with Douglas College evaluation policy. An evaluation schedule is presented at the beginning of the course.
Learning outcomes
Upon successful completion, the student will be able to:
- spot check lenses for surface quality
- verify the power of a single vision lens with the lensometer
- mark the optical centre and major reference point of a single vision lens
- calculate horizontal and vertical lens centration
- calculate lens blank size requirements
- equipment for dispensing eyeglasses including the lensometer, pupilometer, distometer, lens clock ruler and thickness callipers
- perform the process of lens edging
- edge polish lenses
- perform lens insertion and mounting with various frame designs and materials
- define ophthalmic terms pertaining to frame materials, designs, fitting and adjustments
- perform frame fitting and adjustments
Textbook materials
A list of required and optional textbooks and materials is provided for students at the beginning of each semester.