Eye Movement Patterns of the Elderly during Stair Descent: Effect of Illumination
| Autor: | Yuko Ohno, Satoko Kasahara, Naoko Nakazato, Sonoko Okabe |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
medicine.medical_specialty
Visual acuity genetic structures business.industry Eye movement eye diseases Visual field Optics Physical medicine and rehabilitation Stair descent Fixation (visual) Peripheral vision Central vision medicine Elderly people sense organs Electrical and Electronic Engineering medicine.symptom business Psychology |
| Zdroj: | Journal of Light & Visual Environment. 31:134-140 |
| ISSN: | 1349-8398 0387-8805 |
| DOI: | 10.2150/jlve.31.134 |
| Popis: | The relationship between the eye movement pattern during stair descent and illumination was studied in 4 elderly people in comparison with that in 5 young people. The illumination condition was light (85.0±30.9 lx) or dark (0.7±0.3 lx), and data of eye movements were obtained using an eye mark recorder. A flight of 15 steps was used for the experiment, and data on 3 steps in the middle, on which the descent movements were stabilized, were analyzed. The elderly subjects pointed their eyes mostly directly in front in the facial direction regardless of the illumination condition, but the young subjects tended to look down under the light condition. The young subjects are considered to have confirmed the safety of the front by peripheral vision, checked the stepping surface by central vision, and still maintained the upright position without leaning forward during stair descent. The elderly subjects, in contrast, always looked at the visual target by central vision even under the light condition and leaned forward. The range of eye movements was larger vertically than horizontally in both groups, and a characteristic eye movement pattern of repeating a vertical shuttle movement synchronous with descent of each step was observed. Under the dark condition, the young subjects widened the range of vertical eye movements and reduced duration of fixation. The elderly subjects showed no change in the range of eye movements but increased duration of fixation during stair descent. These differences in the eye movements are considered to be compensatory reactions to narrowing of the vertical visual field, reduced dark adaptation, and reduced dynamic visual acuity due to aging. These characteristics of eye movements of the elderly lead to an anteriorly leaned posture and lack of attention to the front during stair descent. |
| Databáze: | OpenAIRE |
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