Spectacle application and manufacturing (10 ECTS)

Objective

Knowledge base
Students are able to
• distinguish between the correction of myopia, hyperopia and astigmatism
• explain prescription entries
• distinguish between different lens types and coatings and describe their intended use
• compare the properties of different lens materials and lens structures, including strong powers
• describe the structure of the focimeter
• distinguish between frame materials and their properties
• draw conclusions about the possibilities and limitations of the use of different lens and frame materials

Clinical/practical
Students are able to
• measure the pupil distance for spectacles distance and near
• take the measurements for a single power lenses, bi-focals and multifocals
• determine the required lens size
• measure the diptric power and the prismatic amount of spectacles with a focimeter
• use the equipment necessary for the manufacture (eg. grinding) the spectacles
• grinding the lenses (basic cases) on an automatic machine according to the measurement
• when grinding takes into account measurements and tolerances related to the positioning of spectacles
• perform simple spectacle services and repairs
• adjust the frame to the customer
• use safely the chemicals needed in optician work
• evaluate the quality of manufactured spectacles

Content

• ametropia and correction with spectacles
• prescription marks, definitions of,diopter and prism
• prescription lens powers; flipping from plus cylinder to the minus cylinder
• the physical properties of the lens
• surface geometry: spherical, cylindrical, toric and aspherical
• lens shape
• edge and center thickness
• definition of lens size and shape
• lens materials
• base curve
• refractive indices
• different surface treatments including a hard and non-reflective surface
• the optical properties of the lens
• the optical axis of the lens, the optical center, the geometric center and the most important measuring points
• the principle of corrective lenses
• prism effect due to decentration in the finished pair of spectacles
• different lens types
• -1-power, bi-focal and tri focal and multifocals for general use and near-viewing
• photochromic lenses
• measuring the pupil distance (distant and near), height, inclination, tilt angle, and lens curvature, determining the lens size
• frame materials, parts, manufacturing and marks, boxing system, frame selection also for high ametropias, physical and biocompatible requirements and adjusting of frames, framing and history of frames, durability of frames and material allergy
• 1-power, bi-focals and multifocals plastic lenses; centering and grinding into frames made of different materials according to the order, finishing of the edges, making lenses smaller and positioning of the lenses in the frame
• standards of the spectacle lenses and tolerances (EN, ISO)
• simple services and repairs of frames and replacement of spare parts
• adjust spectacles to passed on conditions and adjust them for customer
• focimeter; optics and use
• equipment for taking measurement, repairing and manufacturing spectacles
• chemical substances used in optician's work and chemical safety

Location and time

Autumn semester 2023, Myllypurontie 1

Materials

Pointed literature
Spectacle Lenses: Theory and Practice. Colin Fowler, Keziah Latham Petre. Boston: Butterworth-Heinemann, 2001
SYSTEM FOR OPHTHALMIC DISPENSING. Clifford Brooks, Irvin Borish. Elsevier Health Sciences 2006
Ophthalmic Lenses & Dispensing. Mo Jalie SMSA FBDO(Hons) HonFCGI HonFCOptom MCMIgt. 1999
Materials & Treatments, Essilor
Pinnoitteet, Essilor
Lecture materials
Pointed articles
workshop
Spectacle frames and lenses. The student prepare and repair glasses on the materials provided.
The student prepare spectacles in accordance with the instructions given.
Eyeglass lenses are made of plastic, glass and polycarbonate.
The student will repair broken celluloid acetate and metal frames
The student is trained in the use of a lensmeter.

Teaching methods

Interactive lecture
Lecture
Guided assignments
Individual or group assignment
Workshop work

Employer connections

N/A

Exam schedules

Spectacle Frames and Lenses exam 11.10.2023,
first retake 7.11.2023
second retake 12.12.2023.
Workshop: The student's work is evaluated together with the student at the end of the course.

International connections

N/A

Completion alternatives

N/A

Student workload

Spectacle Frames, Tanja Lehti 2 ECTS
Spectacle Lenses, Saija Flinkkilä 3 ECTS
Workshop, Tanja Lehti and Johan Lehti 5 ECTS

Further information

Detailed contents
Spectacle lens prescriptions for ametropia
Physical characteristics of ophthalmic lenses
Geometry of lens surfaces (spherical, cylindrical)
Lens form and lens thickness (centre, edge)
Materials (index of refraction, dispersion, hardness)
Optical and spectacle frame consideration of high-powered lenses: spheric, aspheric and high index materials
Basics of photochromic lenses
Methods of remedying reflections and secondary images
Measuring the pupil distance
Measuring the hight distance
Measuring the diameter of the lens
Spectacle frames history
Physical characteristics and biological compatibility of frame materials
Specification and nomenclature of spectacle frame components
Physical requirements of frame materials
Spectacle Applications
Frame and lens design and manufacturing, including types of single vision and multiple focal lenses, kinds of lens materials, base curves and cylinder forms, character and placement of multi-focals, optical centres and frame specifications.
Fitting and adjusting frames for the wearer
Patient counselling information associated with the dispensing of prescriptions for different ametropias
Eyewear Busines
Practice with a lensmeter
Fitting plastic and metal frames

Evaluation scale

0-5

Assessment criteria, satisfactory (1)

Student is able to:
- Display learning in core content
- Use individual professional concepts correctly
- Find information for a specific situation
- Distinguish between non-theoretical and theoretical information
- Act in individual professional situations as instructed
- Display learning in his professional field
- Show that he has achieved the targets for core competence
- Follow safety instructions
- Display learning in the ethical principles of his professional field
- Operate as a member of a student group

Assessment criteria, good (3)

Student is able to:
- Display an understanding of concepts and professional knowledge in the field
- Assess and limit the amount of information needed
- Operate well in typical professional duties and contexts
- Operate in a multicultural environment
- Operate safely
- Act according to professional ethics
- Operate in a student group

Assessment criteria, excellent (5)

Student is able to:
- Use concepts and knowledge in his field systematically
- Assess and use various information sources
- Apply professional information in professional assignments
- Work in various duties in a variety of operating environments
- Act independently and responsibly in professional contexts
- To take safety issues into consideration in his action
- Argue his choices on the basis of professional ethics
- Organise the activities of a group of students

Assessment criteria, approved/failed

Student is able to:
- Display learning in core content
- Use individual professional concepts correctly
- Find information for a specific situation
- Distinguish between non-theoretical and theoretical information
- Act in individual professional situations as instructed
- Display learning in his professional field
- Show that he has achieved the targets for core competence
- Follow safety instructions
- Display learning in the ethical principles of his professional field
- Operate as a member of a student group

Assessment methods and criteria

Exam and written assignment
Learning assignment
Continuous assessment
Attendance 80 %
The student's work is evaluated together with the student at the end of the course.
Pupil distance tolerance 0.5 -1.0 mm / lens
The height tolerance 0.5 mm / lens
Axis direction tolerance from 1 degree to 5 degrees

Qualifications

No