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自1990年5月1日起我科采用对数视力表与5分记录法来测量与统计视力,深感对数视力表与5分记录法在设计、记录等方面都明显优于国际标准视力表,体会如下。视标设计符合人体感觉生理学的客观规律一、对数视力表采用对数原理将视标增率定为K=10~(1/10)=1.2589……,因此任何相邻二行视标大小之比恒为10~(1/10)=1.2589,每隔10行差10倍。再将K之对数值Log1.2589=0.1作为视力记录差数。如此,每行记录差0.1,10行差1.0。这样视标(即视角)每增大1.2589倍,视力记录就减0.1,视标增大(1.2589)~2倍,则记录减0.2,反之亦同。即视标按几
Since May 1, 1990, our department has adopted the logarithmic visual acuity chart and the 5-point recording method to measure and visual acuity. The deep logarithmic visual acuity chart and the 5-point recording method are obviously superior to the international standard visual acuity Table, experience as follows. As the design of the visual target in line with the objective laws of human physiology First, the logarithmic visual acuity principle using the logarithmic multiplication as K = 10 ~ (1/10) = 1.2589 ... ..., so any adjacent two rows of visual target size The ratio of constant 10 ~ (1/10) = 1.2589, 10 times every 10 lines difference. Then the logarithm of K Log1.2589 = 0.1 as the difference between eyesight records. So, each line record difference 0.1,10 line difference 1.0. Such as the visual target (ie perspective) 1.2589 times each increase, decreased visual acuity 0.1, visual target increased (1.2589) ~ 2 times, the record minus 0.2, and vice versa. That is, depending on the standard by a few