Accommodation in humans with juvenile macular degeneration
| Autor: | Bruce Wick, Janis M. White |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Adult
Accommodation Visual acuity genetic structures Eye disease Visual Acuity Stimulus (physiology) Contrast Sensitivity Macular Degeneration Optics Vision Monocular Vergence medicine Humans Vision Binocular Monocular business.industry Accommodation Ocular Proximal Juvenile macular degeneration medicine.disease eye diseases Sensory Systems Ophthalmology Stargardt's disease Optometry sense organs Cues medicine.symptom Psychology business Depth perception Monocular vision Binocular vision |
| Zdroj: | Vision Research. 35:873-880 |
| ISSN: | 0042-6989 |
| DOI: | 10.1016/0042-6989(94)00181-k |
| Popis: | Accommodation, or the change in refractive power of the eye to focus objects at different distances, is driven by many stimuli including defocus blur, the awareness of target distance or proximal cues, and through the vergence crosslink (convergence acccommodation). The effectiveness of defocus blur as an accommodative stimulus is decreased in normally-sighted subjects as visual acuity is experimentally reduced and as the target is imaged at increasing eccentricities from the fovea. Since subjects with central retinal abnormalities have reduced visual acuity and typically fixate eccentrically, one would predict that defocus blur would not be an effective accommodative stimulus for them. Using an infrared optometer, steady-state accommodative responses of six subjects with juvenile macular degeneration (JMD) and of three normally-sighted controls were measured. The effectiveness of defocus blur in stimulating accommodation varied across the subjects and was related to visual acuity, with those subjects having worse acuity showing less accurate accommodative responses. When provided with additional cues to accommodative demand (i.e. proximal and/or binocular cues), subjects with JMD showed more accurate accommodative responses. In general, those subjects who did not modulate accommodative response with changing defocus blur cues showed the most accurate accommodation under binocular viewing. In contrast, those subjects who did change accommodative response with changing defocus blur cues showed the most accurate accommodation under monocular viewing. |
| Databáze: | OpenAIRE |
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