The condition of the normal eye when parallel rays are focused exactly on the retina and vision is perfect 屈光正常當平行光線恰好聚焦于視網(wǎng)膜并形成清晰視覺時正常眼睛的狀態(tài)
An analysis is made about descartes rays of transparent round - section fibers - a special internal surface reflection rays of the fiber when parallel rays strike the fibers perpendicularly to fiber axis 摘要分析了透明圓形截面纖維在垂直纖維軸光線照射時紗維內(nèi)表面反射光的一種特殊現(xiàn)象笛卡爾線現(xiàn)象。