Norcia A M, Zadnik K, Day S H
Acta Ophthalmol (Copenh). 1986 Aug;64(4):379-85. doi: 10.1111/j.1755-3768.1986.tb06939.x.
Kaakinen (1979) presented a method of measuring refractive error and ocular alignment by simultaneous photography of corneal and fundus reflexes. As presented, the technique was unable to detect refractive errors of less than 2-3 diopters (Howland 1980; Kaakinen 1979). We demonstrate that the use of a catadioptric lens and a long working distance can improve sensitivity to less than 1.0 D. Refractions of a model eye, an accommodating eye and ametropic eyes indicate that refractive errors greater than 0.75 D are readily detectable. The improvement in sensitivity achieved by the present system is attributable to a reduction of the angle between the flash source and the entrance pupil of the photorefractor.
卡基宁（1979年）提出了一种通过同时拍摄角膜和眼底反射来测量屈光不正和眼位的方法。如所呈现的那样，该技术无法检测到小于2 - 3屈光度的屈光不正（霍兰德1980年；卡基宁1979年）。我们证明，使用折反射透镜和长工作距离可以将灵敏度提高到小于1.0屈光度。对模型眼、调节眼和屈光不正眼的验光表明，大于0.75屈光度的屈光不正很容易被检测到。本系统所实现的灵敏度提高归因于闪光光源与 photorefractor（验光仪）入瞳之间夹角的减小。
