Roorda A, Bobier W R, Campbell M C
School of Optometry, University of Waterloo, Ontario, Canada.
Vision Res. 1998 Jun;38(13):1913-24. doi: 10.1016/s0042-6989(97)00424-0.
An objective infrared optometer has been designed, based on the optical principles of eccentric photorefraction. A CCD camera with an eccentric infrared light source images the subject's pupil through a Badal optometer. The slope of the light distribution across the pupil is continuously recorded. Accommodative state is measured by moving the camera behind the Badal lens until the slope is zero. This position corresponds to the case where the camera is conjugate with the retina of the observer. In this Badal optometer, the irradiance of light at the pupil plane, the sensitivity of the photorefractor, and the focal setting of the camera lens remain constant for all positions of the camera from the eye. The repeatability of a single measure of refractive state in a cyclopleged eye was less than 0.05 D. Static accommodative responses taken from 3 subjects in both closed and open loop conditions provided expected stimulus/response measures. The instrument can also be adapted to measure dynamic accommodation.
基于偏心摄影验光的光学原理，设计了一种客观红外验光仪。带有偏心红外光源的CCD相机通过巴达尔验光仪对受试者的瞳孔进行成像。连续记录穿过瞳孔的光分布斜率。通过将相机移至巴达尔透镜后方直至斜率为零来测量调节状态。此位置对应于相机与观察者视网膜共轭的情况。在这种巴达尔验光仪中，对于相机相对于眼睛的所有位置，瞳孔平面处的光照度、摄影验光仪的灵敏度以及相机镜头的焦距设置均保持恒定。在睫状肌麻痹的眼睛中，单次测量屈光状态的重复性小于0.05 D。在闭环和开环条件下，对3名受试者进行的静态调节反应提供了预期的刺激/反应测量结果。该仪器还可用于测量动态调节。
