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KMID : 1011420120170040411
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Journal of Korean Ophthalmic Optics Society
2012 Volume.17 No. 4 p.411 ~ p.417
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Changes of Contrast Sensitivity with Decreasing Luminance in Photopic Conditions
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Lee Eun-Jin
Yoon Moon-Joo
Kim Soo-Hyun
Yang Gye-Tak
Jeong Ju-Hyun
Kim Hyun-Jung
Kim Hyun-Il
Choi Eun-Jung
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Abstract
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Purpose: To investigate changes of contrast sensitivity with decreasing luminance in photopic conditions. Methods: Contrast sensitivities for 63 university students were investigated at 5 different luminance levels using FACT chart. Results: All contrast sensitivities measured were in the normal range. The peak of contrast sensitivity function was observed to move from 6 to 3 cpd between 40 and 10 cd/m2. From an intersection point of two hypothetical lines related with contrast sensitivity for 6 and 3 cpd, we could evaluated that the peak moved from 6 to 3 cpd at about 25 cd/m2. When luminance decreases from 120 to 10 cd/m2, contrast sensitivity loss at 6 cpd was most, while contrast sensitivity at 1.5 cpd changed little. We could evaluate that at luminance of more than 25 cd/m2 evaluated approximately, contrast sensitivity was high in the following order of spatial frequency: 18< 12<1.5<3<6 cpd, while at luminance of less than about 25 cd/m2 as follows: 18<12<1.5<6<3 cpd. Contrast sensitivity losses with decreasing luminance were also evaluated using the decrements and decrement rates of contrast sensitivity. The decrement of contrast sensitivity was the greatest at 6 cpd, while the decrement rate was the greatest at 8 cpd. Conclusions: We propose that evaluation methods used in this research may be available as another methods to evaluate the changes of contrast sensitivity.
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KEYWORD
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Luminance, Contrast sensitivity, Peak, Spatial frequency
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