Stereoscopic acuity in ocular pursuit of moving objects : Dynamic stereoscopy and movement parallax: relevance to road safety and occupational medicine
There has been growing acceptance of the insight that the methods so far used in the testing of visual functions have been inadequate when it comes to specific problems and should, therefore, be supplemented with more specialised methods for dynamic testing. As long as two decades ago, large-scale mass screening produced evidence to the effect that visual acuity, so far exclusively determined by means of still samples, was not identical with visual acuity in the ocular pursuit of moving targets (dynamic visual acuity). In other words, vision testing can, at present, provide little informa- tion on an individual's capability of identification, appreciation, and judge- ment of mobile objects. Spatial, three-dimensional perception of moving targets, hereafter re- ferred to as dynamic stereoacuity, is the particular subject on which findings are reported in this article. Findings of that kind are of considerable relevance to everyday life, since many of the phenomena that have to be three-dimensionally perceived in private life and in occupational practice, are in movement. So far, dynamic stereoacuity has never been systematical- ly studied and is still a blank space on the maps of ophthalmology and physiology. This is equally true for dynamic stereoscopy in binocular vision as well as for perception on the basis of movement parallax, a phenomenon of differentiated contour displacement within a given field of vision which is also available to the monocular individual under conditions of head or body or object movement within the visual space.
- Paperback | 136 pages
- 154.94 x 234.95 x 7.87mm | 263.08g
- 01 Jan 1992
- Dordrecht, Netherlands
- Softcover reprint of the original 1st ed. 1991
- 136 p.
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Table of contents
Preface.- 1 Introduction.- 2 Elements of dynamic stereoscopic vision.- 2.1 Monocular dynamic visual acuity.- 2.1.1 Effects of mode of movement.- 2.1.2 Dynamic visual acuity due to eye alterations.- 2.2 Stereoscopic vision.- 2.2.1 Determination of static stereoacuity.- 2.2.2 Quality of stereoacuity.- 2.3 Dynamic parallactoscopy.- 2.3.1 Testing equipment.- 2.4 More empirical factors of stereoscopic vision.- 2.5 Dynamic vision.- 3 Equipment and methods for testing dynamic stereoacuity.- 3.1 Determination of dynamic stereoacuity.- 3.1.1 Binocular rotational prismometer.- 3.1.2 Test object.- 3.1.3 Testing method.- 3.2 Determination of kinetoparallactic stereoacuity.- 3.2.1 Parallactoscopometer.- 3.2.2 Test object.- 3.2.3 Testing method.- 4 Normal values of dynamic stereoacuity.- 4.1 Dynamic stereoacuity.- 4.1.1 Mean values and standard deviation.- 4.1.2 Effect of age.- 4.1.3 Effect of sex.- 4.1.4 Effect of occupational activity.- 4.1.5 Comparison between dynamic stereoacuity and dynamic visual acuity.- 4.2 Dynamic parallactoscopy.- 4.2.1 Mean values and standard deviation.- 4.2.2 Effects of age and static visual acuity.- 4.2.3 Effects of sex and occupational activity.- 4.2.4 Comparison between right and left eyes.- 4.2.5 Comparison between active and passive movement parallax.- 5 Variations of test objects and testing methods.- 5.1 Dynamic stereoacuity.- 5.1.1 Various circular movements.- 5.1.2 Variations in bar thickness.- 5.1.3 Variations in bar spacing.- 5.1.4 Variations in bar height.- 5.1.5 Depth distance of only two bars.- 5.1.6 Depth distance of two surfaces.- 5.2 Dynamic parallactoscopy.- 5.2.1 Variations in bar thickness.- 5.2.2 Variations in bar spacing and bar height.- 5.2.3 Depth distance of two and five bars.- 5.2.4 Double triangular test.- 5.2.5 Variations in image time and object speed.- 5.2.6 Variations in direction of movements.- 6 Dynamic stereoacuity in response to changes in perception conditions.- 6.1 Dynamic stereoacuity.- 6.1.1 Bilateral impairment of visual acuity.- 6.1.2 Unilateral impairment of visual acuity.- 6.1.3 Conditions of scotopic vision.- 6.1.4 Unilateral light absorption.- 6.1.5 Anisometropia.- 6.2 Dynamic parallactoscopy.- 6.2.1 Impairment of visual acuity.- 6.2.2 Conditions of scotopic vision.- 7 Effect of psychosensorial factors.- 7.1 Fatigue.- 7.2 Effect of psychosedatives.- 7.3 Effect of hypnotics.- 7.4 Short-time and long-time exercises.- 7.5 Asthenopia.- 8 Comparison between dynamic and kinetoparallactic stereoacuities.- 9 Conclusions.