Optics of the Spectacle Lenses (5 cr)

Objective

Students are able to
• describe and solve problems by calculating and drawing a human eye as an optical system
• calculate power effect in different vertex distance
• calculate, measure and describe the effect of prism on spectacle lenses and the elimination of unwanted prism effect and use of that in the purpose meaning
• calculate and describe the magnification effect of spectacles and design solutions in the case of aniseiconic cases

Themes are sphero-cylindrical lenses, thin prisms, prismatic effect and the manipulation of lens form and setting to obtain the desired control of prismatic effect.

Content

Eye models and sphero-cylindrical lenses
o ametropias and refraction of the principal meridians
o sphero-cylindrical lenses and the location of foci, image planes, principal meridians, least blur confusion
o dioptric distributions in lenses, also between principal meridians
Lens prismatic effect
o Prentice formula
o manipulation of lens form and setting to obtain the desired control of prismatic effect horizontal and vertical meridian
o vertical prism effect
Schematic eye models:
• Dioptric components
• Cardinal points, entrance and exit pupils
• Ametropia: far point, near point, correction
• Accommodation: amplitude and effectivity
• Astigmatism, including correction
• Retinal image size, spectacle magnification, and relative spectacle magnification
• Apertures
• Entrance and exit pupil size and location
Optics of the eye:
• Characteristics of components (curvature, thickness, separation, refractive indices, and axial length)
• Reference angles and axes
• Retinal image size
• Optical function of the pupil – depth of field
Spectacle lenses:
• geometry of the lens surface: aspherical and atoric lenses
• Power effect distance and near and vertex distance
• spectacle magnifications
o shape and power factors
o relative spectacle magnifications
o iseiconic lenses
• lens prism and prismatic effect
o thickness differences in lens by the prism
o combination of thin prisms
o resolution of an oblique prism into horizontal and vertical components, oblique prism
o prism effect in near distances
• vertical prism eliminations aniseiconic cases
o Slab off, prism segment, Fresnell prism, taking account of height
• lens induced problems; aberrations, weight, thickness, limits of field, secondary images, magnification, jump and displacement in spherical and sphero-cylindrical lenses

Location and time

Myllypuro Campus. If needed lessons will be on web or combination of lessons and web-studies. Teacher of the course will give further information before the beginning of the course.

Materials

To be announced

Teaching methods

Lessons
Learning assignments

Employer connections

-

Exam schedules

Exam 19.5.2025 on Campus.
I retake: 2.-7.6.2025, Exam-retake
II retake: Autumn 2025, Exam-retake
Dates for retakes will be announced later.

Completion alternatives

N/A

Student workload

5 credits = 135 hours work for student
Lessons approx. 36 h
Exam 3 h
Learning assignments approx. 30 h
Independent studying approx. 65 h

Further information

If the student has individualized educational support arrangements, shall this student contact the teacher of the course immediately after the end of the registration period (or latest before the start of the course.)

Instructions on the use of artificial intelligence during the course are given separately. Students should familiarise themselves with Metropolia's AI guidelines and follow them in their study attainments.

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

Continuing assessment, assignments.
The grade of the course is determined based on the exam.
Presence in lectures.