Abstract: The purpose of this study is to examine the .influences of lightsources characterized by linear spectrum on the visual acuity underdifferent adaptation luminances (0.75cd/m~2--125cd/m~2). The results areas follows: 1.The visual acuity under these light sotirces enhanced with theincrease of adaptation luminance, but the increase of visual acuitybecame saturated when the adaptation luminance reached a certaindegree. 2.The visual acuity under sources characterized by linear spectrumis greater than under sources characterized by continuous spectrum, theluminance level remaining unchanged. 3.The difference of visual acuity under high pressure sodiumlamp and that tinder high pressure mercury lamp at all luminance levelsis not significant. 4.The differences between the four sources are not significant atthe luminance levels from 7.5cd/m~2 to 25cd/m~2.

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