OPTICAL AND RETINAL FACTORS AFFECTING VISUAL RESOLUTION
OPTICAL AND RETINAL FACTORS AFFECTING VISUAL RESOLUTION
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DOI：
10.1113/jphysiol.1965.sp007784
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发表时间：
1965-01-01
影响因子：
5.5
通讯作者：
GREEN, DG
中科院分区：
文献类型：
--
作者：
CAMPBELL, FW;GREEN, DG
用氦氖激光器作光源，直接在视网膜上产生干涉条纹，从而避开了人眼光学的影响。测量了这些干涉条纹分辨率的阈值对比度。结果发现，随着空间频率的增加，对比敏感度大致呈指数下降。用示波器上显示的类似正弦光栅测量整个视觉系统的对比敏感度。在所有的空间频率的对比灵敏度被发现是低于所获得的干涉条纹。通过找出这两种技术测量的对比灵敏度之间的比率，计算出由于眼睛的光学特性而导致的对比度降低。确定瞳孔大小和焦点变化对视网膜图像质量的影响。对于具有2 mm直径瞳孔的眼睛，测量的光学衰减与衍射限制系统的预测一致。随着瞳孔尺寸的增加，光学系统的性能逐渐偏离完美的光学系统。光学系统的质量大大优于最近检眼镜方法所确定的质量。
With a neon-helium laser as a light source, interference fringes were produced on the retina directly, thus by-passing the effects of the optics of the eye. Threshold contrasts for resolution of these interference fringes were measured. It was found that the contrast sensitivity decreased roughly exponentially with increase in spatial frequency. The contrast sensitivity of the over-all visual system was measured with similar sinusoidal gratings displayed on an oscilloscope. At all spatial frequencies the contrast sensitivity was found to be lower than that obtained with the interference fringes. By finding the ratio between the contrast sensitivities measured by these 2 techniques, the contrast reduction due to the optics of the eye was calculated. The effects of changes in pupil size and focus on the quality of the retinal image was determined. For an eye with a 2 mm diameter pupil the measured optical attenuation agrees with that predicted for a diffraction-limited system. With increasing pupil size the performance of the optics deviated progressively from a perfect optical system. The quality of the optics is substantially better than that determined by recent ophthalmoscopic methods.