Visual PerceptionLaajuus (5 cr)

Objective

Knowledge base
Students are able to
• describe physical and physiological aspects of vision including the principals of psychophysical measurements and visual perception in the area of: (1) visual pathways, (2) light perception, (3) colour vision, (4) space perception, (5) form perception, (6) motion perception, (7) temporal perception, and (8) basic psychophysical methods and theory.
• describe the basics of the nervous system; (1) electrophysiology of neurons, (2) neuroanatomy (3) neurophysiology a
• assess colour vision, contrast vision and visual fields and normality of test results

Clinical/practical base
Students are able to
• test colour vision
• test contrast sensitivity and low contrast visual acuity
• measure visual fields

Content

Anatomy and physiology of the eye:
Retina
o Composition and formation of disc outersegments
o Composition and formation visual pigments
o Stages of visual cycle
o Photoreceptor electophysiology
o Retinal neurotransmitters
o Function of bipolar, horizontal, amacrine and ganglion cells (receptive fields)
o Retinal neural mechanisms of colour vision (spatial, temporal and chromatic)

Visual pathway
o Function of lateral geniculate body
o Receptive fields of cells in leterat geniculate body (relationship to colour vision, binocularity, grace perception, etc.)
o Function of visual cortex
o Receptive field properties (single cell properties)
o Functional organisation of visual cortex
o Physiology of binocular vision
o Mechanism of featrue detection
Extraocular muscles
• Visual-vestibular interactions (vestibulo-ocular reflex, optokinetic reflex)
• Supranuclear control of eye movements

Anatomy relation to visual pathology

Development of lower visual pathway
• Relationship between development of upper visual pathway and central vision

Electrophysiology of the nerve cell
o Resting and action potential
o Synapses
o Receptors
Neuroanatomy
o Brain
o Cranial nerves
o Spinal cord
o Autonomic nervous system
Neurophysiology
o Reflexes
o Pain and pain sensation
o Vestibular system, propioceptive sensations
o Autonomic nervous system

Colour perception
- Chromatic discrimination (hue and saturation) for normal & defective colour vision
- Colour mixture and appearance
- Colour specification and colorimetry (CIE)
- Spectral sensitivity of normal and defective colour vision
- Mechanisms of colour deficiencies
-
Space perception
- Direction and depth discrimination (monocular and binocular cues, oculocentric and egocentric localization)
- Characteristics of sensory function (binocular interactions including summation, binocular suppression and rivalry, corresponding points including horopter criteria)
- Development of sensory fusion and binocular vision
- Sensory-motor interactions (fixation, disparity, past pointing, visually guided behaviour, body posture and perceived orientation, and self-motion)
-
Form perception
- Static visual acuity (including test configuration, various acuity tasks, and factors influencing acuity including blur, intensity and contrast), specification of visual acuity
- Spatial contrast sensitivity function (including factors influencing the function) illusions, constancies, and figure-ground relations
- Simultaneous contrast and spatial interactions (Mach bands)
-
Light perception
- Detection characteristics at the absolute light threshold (including spectral, spatial, and temporal aspects) specification of contrast
-
Motion perception
- Factors involved in the detection of real and apparent motion, detection of displacements
- Motion after-effects
-
Temporal perception
- Critical flicker fusion frequency, including influencing factors (test object size, location and adaption level)
- Stabilised retinal images and monocular suppression (Troxler effect)
- Saccadic suppression

Psychophysical Methodology
- Basic psychophysical methods and theory
- Measurement of absolute and difference thresholds
- Methods of limits, adjustment, and constant stimuli

Entoptic Phenomena
o Characteristics and origin of various phenomena (involvoing the cornea, lens, and vitreous)
o Vascular and circulatory phenomena (Purkinje tree, capillary circulation)
o Phenomena associated with central vision (Maxwell’s spot, Haidinger’s brushes)
o Phenomena associated with retinal distention or other forms of retinal activity (Moore’s lightning streaks, blue arcs of the retina, phosphenes)
Eccentric fixation (EF) -definition, visual acuity and eccentrisity, test procedure

Tests and procedures:
Colour vision investigation (Ishihara, H.R.R. Farnsworth D-15 saturated and desaturated, Farnsworth-Munsell 100 Hue test)
•Clinical use
•Instrumentation
•Clinical procedure
•Clinical implications

Contrast sensitivity evaluation (Pelli-Robson, Vistech)
•Clinical use
•Instrumentation
•Clinical procedure
•Clinical implications

Perimetry (Amsler, Confrontation method, Bjerrum screen, Goldmann bowl)
•Clinical use
•Instrumentation
•Clinical procedure
•Clinical implications

Anomalies of Colour Vision (Congenital, Inherited)
Colour vision anomalies by type and prevalence
- Anomalous trichromacy
- Dichromacy
- Monochromacy
-
Colour vision tests used for both screening and diagnosis of congenital colour vision anomalies
- Pseudoisochromatic tests
- Arrangement tests (Farnsworth Panel 0-15, Farnsworth-MunseI1100-Hue)
- Anomaloscopic matching
-
Conditions for colour vision testing
-
Societal implications of colour vision anomalies
- School
- Vocational requirements
- Patient interest
-
Patient management strategies
- Counselling
- Special aids

Qualifications

Refraction

Assessment criteria, satisfactory (1)

The student is able to:
- display learning in professional knowledge and core content in the field
- search information from a variety of sources
- work in various duties in a variety of operating environments
- show that he has achieved the targets for core competence
- display learning in the key safety practices in the field
- act according to ethical principles
- to contribute his learning for the benefit of a group or project

Assessment criteria, good (3)

The student is able to:
- use concepts and knowledge in his field systematically
- find information and assess and use information sources with a critical eye
- apply professional information in professional assignments
- apply professional expertise in various work assignments
- act independently and responsibly in professional contexts
- plan operations with safety in mind
- act according to professional ethics
- act purposefully in working groups and projects

Assessment criteria, excellent (5)

The student is able to:
- use concepts and knowledge in his field professionally
- argue the use of his sources - argue a course of action on the basis of research information or findings
- operate in a range of duties and work situations, also in international contexts
- to act in a way that is customeroriented and displays entrepreneurial spirit
- to act responsibly, taking safety issues into consideration
- argue his choices on the basis of professional ethics
- organise and manage the operation of a group and project

Assessment criteria, approved/failed

The student is able to:
- display learning in professional knowledge and core content in the field
- search information from a variety of sources
- work in various duties in a variety of operating environments
- show that he has achieved the targets for core competence
- display learning in the key safety practices in the field
- act according to ethical principles
- to contribute his learning for the benefit of a group or project