Degradation of vision through a simulated cataract.
Degradation of vision through a simulated cataract.
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通过模拟白内障导致视力下降。
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
M. Keller
中科院分区：
文献类型：
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作者：
J. Zuckerman;D. Miller;W. Dyes;M. Keller
除了致密核型白内障外，大多数白内障通过散射入射光而干扰视力。散射以及因此的图像退化可以通过在表面上压有凡士林斑点的玻璃透镜来模拟。利用这种系统，可以通过用凡士林覆盖的玻璃透镜表面的量来控制“白内障百分比”。模拟白内障是F-5透镜系统的一部分，该系统最好地模拟了具有3.5 mm瞳孔的眼睛的几何光学系统。该研究确定了作为白内障百分比的函数的模拟白内障透镜的传递函数。使用照相和显微密度测量技术。结果显示了白内障百分比、分辨率和对比度之间的精确关系。例如，首先注意到对比度下降的小角度对向的条形目标与40%的白内障，而对比度保持不变，直到80%的白内障是达到如果大角度对向的条形目标被视为。
Most cataracts, apart from the dense nuclear sclerotic type, interfere with vision by scattering the incident light. The scattering, and therefore the image degradation, may be simulated by a glass lens with petroleum jelly spots pressed on the surface. With such a system, "per cent of cataract" can be controlled by the amount of surface of the glass lens covered with petroleum jelly. The simulated cataract was part of an F-5 lens system which best simulated the eye's geometric optical system with a 3.5 mm. pupil. The study determined the transfer function of the simulated cataractous lens as a function of the per cent of cataract. Photographic and microdensitometric techniques are used.. The results show the precise relationship between per cent cataract, resolution, and contrast. For example, contrast is first noted to drop for bar targets of small angular subtense with a 40 per cent cataract whereas, contrast remains constant until an 80 per cent cataract is reached if bar targets of large angular subtense are viewed.