655-220 Physiological Optics

Coordinator:

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Objectives:

On completion of this subject students will:

• have a thorough understanding of the capabilities of the human visual system;

• be familiar with the classical theories of visual function;

• have a systematic understanding of the physiological processes underlying vision and a general understanding of the theoretical models that explain visual function and the processing of visual information by the visual pathways and visual cortex;

• understand the control of oculo-motor behaviour;

• have a general understanding of the processes of post-natal development;

• understand the physiological and biochemical mechanisms that maintain the integrity of the eye;

• have the skills to measure a range of visual functions and understand classical visual psychophysical methodology.

Content:

Human visual functions Specification of the stimulus; the radiometric and photometric quantities. The light sense: spectral luminous efficiency; absolute threshold and quantum effects; light and dark adaptation: increment thresholds. Temporal resolution; flicker and transient stimulation. The form sense: visual acuity and the contrast sensitivity function. The colour sense: the trivariance of vision and the systems for specifying chromaticity; colour discriminations; theories of colour vision. Perception of visual space: projection, retinal correspondence, the horopter, fusion and stereopsis. Physiology of the visual processes The photoreceptors: optics, photochemistry, transduction. Retinal structure and function. Contrast and colour coding in the retina. Cortical structure and function. Development of normal visual function. Muscular mechanisms of the eye. Extra-ocular musculature; the mechanics of translatory, saccadic and slow pursuit eye movements. Listing's Law. Neural control of eye movements and binocular eye movements. Hering's Law. Accommodation, accommodative-convergence synkinesis. Pupillary reactions. Vegetative physiology of the eye The cornea; the anatomy and physical properties of the cornea; the chemistry and metabolism of the cornea, corneal permeability, turgescence and maintenance of transparency. The lacrimal apparatus and the tear film. The sclera. Formation and circulation of aqueous humour, intra-ocular pressure. The physical properties, biochemistry, growth and metabolism of the lens. Vegetative physiology of the retina and vitreous.

Assessment:

Prescribed Texts:

• Davson H, Physiology of the Eye, 5th ed. 1990 Mosby.
• Kuffler S W, Nicholl J G and Martin A R, From Neuron to Brain, 3rd ed. 1992 Sinauer Assoc. Inc.