Stray Light of Spectacle Lenses Compared with Stray Light in the Eye
作者:
GERARD DE WIT,
and JORIS COPPENS,
期刊:
Optometry and Vision Science
(OVID Available online 2003)
卷期:
Volume 80,
issue 5
页码: 395-400
ISSN:1040-5488
年代: 2003
出版商: OVID
关键词: scattering;glare;ophthalmic optics;vision
数据来源: OVID
摘要:
Stray light in spectacle lenses may affect the overall vision. It may also affect the measurement of ocular stray light, contrast sensitivity, or glare sensitivity. This article describes common stray light characteristics for glass and plastic spectacle lenses and compares this to the stray light characteristics of the eye, which are well known from the literature. Stray light is described by the skirts of the point-spread function (PSF), which were measured for angles from 4° to 30°. The PSF of spectacle lenses appears to follow the equation PSF = a10· (&thgr;/10)b, with a10and b representing fitting parameters and &thgr; representing the stray light angle. The slope b is on average −2, which similar to that of the eye. For clean spectacle lenses, the PSF is usually at least an order of magnitude lower than that of the eye, whereas “as worn” (uncleaned) spectacle lenses may approach the PSF of the eye. To reach the PSF of the eye, the spectacle lens needs to be contaminated by as much as one or two fingerprints. The article also shows that plastic spectacle lenses degrade much faster than glass spectacle lenses when looking at the amount of stray light.
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