Night myopia studied with an adaptive optics visual analyzer.
PURPOSE: Eyes with distant objects in focus in daylight are thought to become myopic in dim light. This phenomenon, often called "night myopia" has been studied extensively for several decades. However, despite its general acceptance, its magnitude and causes are still controversial. A ser...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3388063?pdf=render |
| _version_ | 1818043694361608192 |
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| author | Pablo Artal Christina Schwarz Carmen Cánovas Alejandro Mira-Agudelo |
| author_facet | Pablo Artal Christina Schwarz Carmen Cánovas Alejandro Mira-Agudelo |
| author_sort | Pablo Artal |
| collection | DOAJ |
| description | PURPOSE: Eyes with distant objects in focus in daylight are thought to become myopic in dim light. This phenomenon, often called "night myopia" has been studied extensively for several decades. However, despite its general acceptance, its magnitude and causes are still controversial. A series of experiments were performed to understand night myopia in greater detail. METHODS: We used an adaptive optics instrument operating in invisible infrared light to elucidate the actual magnitude of night myopia and its main causes. The experimental setup allowed the manipulation of the eye's aberrations (and particularly spherical aberration) as well as the use of monochromatic and polychromatic stimuli. Eight subjects with normal vision monocularly determined their best focus position subjectively for a Maltese cross stimulus at different levels of luminance, from the baseline condition of 20 cd/m(2) to the lowest luminance of 22 × 10(-6) cd/m(2). While subjects performed the focusing tasks, their eye's defocus and aberrations were continuously measured with the 1050-nm Hartmann-Shack sensor incorporated in the adaptive optics instrument. The experiment was repeated for a variety of controlled conditions incorporating specific aberrations of the eye and chromatic content of the stimuli. RESULTS: We found large inter-subject variability and an average of -0.8 D myopic shift for low light conditions. The main cause responsible for night myopia was the accommodation shift occurring at low light levels. Other factors, traditionally suggested to explain night myopia, such as chromatic and spherical aberrations, have a much smaller effect in this mechanism. CONCLUSIONS: An adaptive optics visual analyzer was applied to study the phenomenon of night myopia. We found that the defocus shift occurring in dim light is mainly due to accommodation errors. |
| first_indexed | 2024-12-10T09:06:17Z |
| format | Article |
| id | doaj.art-6770aef9545240afa489c109e5116e50 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-10T09:06:17Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-6770aef9545240afa489c109e5116e502022-12-22T01:55:08ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0177e4023910.1371/journal.pone.0040239Night myopia studied with an adaptive optics visual analyzer.Pablo ArtalChristina SchwarzCarmen CánovasAlejandro Mira-AgudeloPURPOSE: Eyes with distant objects in focus in daylight are thought to become myopic in dim light. This phenomenon, often called "night myopia" has been studied extensively for several decades. However, despite its general acceptance, its magnitude and causes are still controversial. A series of experiments were performed to understand night myopia in greater detail. METHODS: We used an adaptive optics instrument operating in invisible infrared light to elucidate the actual magnitude of night myopia and its main causes. The experimental setup allowed the manipulation of the eye's aberrations (and particularly spherical aberration) as well as the use of monochromatic and polychromatic stimuli. Eight subjects with normal vision monocularly determined their best focus position subjectively for a Maltese cross stimulus at different levels of luminance, from the baseline condition of 20 cd/m(2) to the lowest luminance of 22 × 10(-6) cd/m(2). While subjects performed the focusing tasks, their eye's defocus and aberrations were continuously measured with the 1050-nm Hartmann-Shack sensor incorporated in the adaptive optics instrument. The experiment was repeated for a variety of controlled conditions incorporating specific aberrations of the eye and chromatic content of the stimuli. RESULTS: We found large inter-subject variability and an average of -0.8 D myopic shift for low light conditions. The main cause responsible for night myopia was the accommodation shift occurring at low light levels. Other factors, traditionally suggested to explain night myopia, such as chromatic and spherical aberrations, have a much smaller effect in this mechanism. CONCLUSIONS: An adaptive optics visual analyzer was applied to study the phenomenon of night myopia. We found that the defocus shift occurring in dim light is mainly due to accommodation errors.http://europepmc.org/articles/PMC3388063?pdf=render |
| spellingShingle | Pablo Artal Christina Schwarz Carmen Cánovas Alejandro Mira-Agudelo Night myopia studied with an adaptive optics visual analyzer. PLoS ONE |
| title | Night myopia studied with an adaptive optics visual analyzer. |
| title_full | Night myopia studied with an adaptive optics visual analyzer. |
| title_fullStr | Night myopia studied with an adaptive optics visual analyzer. |
| title_full_unstemmed | Night myopia studied with an adaptive optics visual analyzer. |
| title_short | Night myopia studied with an adaptive optics visual analyzer. |
| title_sort | night myopia studied with an adaptive optics visual analyzer |
| url | http://europepmc.org/articles/PMC3388063?pdf=render |
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