Fariza E, Kronheim J, Medina A, Katsumi O
Eye Research Institute, Boston, MA.
Jpn J Ophthalmol. 1990;34(3):314-9.
To test visual acuity in children, we developed a chart constructed so that the mean Fourier transform of the luminance of the figures on the chart at zero spatial frequency is the same as the background luminance. When the eye reaches its limit of resolution, the figures vanish into the gray background of the chart rather than becoming "blurred" as in conventional visual acuity charts. We compared the number of errors in determining the visual acuity of children aged 3-4.5 years using this high-frequency chart and a standard black-and-white high-contrast chart. Significantly fewer errors were found with the high-frequency chart, suggesting that this type of testing may improve the accuracy of visual acuity measurements in children.
为了测试儿童的视力，我们设计了一种视力表，其构造使得视力表上图形亮度在零空间频率时的平均傅里叶变换与背景亮度相同。当眼睛达到其分辨率极限时，图形会融入视力表的灰色背景中，而不像传统视力表那样变得“模糊”。我们比较了使用这种高频视力表和标准黑白高对比度视力表来测定3至4.5岁儿童视力时的错误数量。结果发现，使用高频视力表时的错误明显更少，这表明这种测试方式可能会提高儿童视力测量的准确性。
