Hendrikse, Egbert Johannes (1994) Influence of blue/green versus red and white light sources on human dark adaptation and other selected visual functions. PhD thesis, Rhodes University.
Red interior lighting used to preserve dark-adaptation needs to be replaced in military applications by blue/green lighting which is not detectable by 3rd-generation image intensifiers. This study investigated the influence of blue/green as compared to red and white light of equal photopic intensity on subsequent visual acuity , contrast sensitivity and dark-adaptation. Male subjects (n = 90) were assigned to one of 15 treatment conditions (n = 6) as determined by the colour (blue/green, red or white) and intensity (0.1; 0.4; 1.6; 6.4 and 25.6 cd/m²) of the pre-adaptation stimuli. A modified Goldmann/Weekers adaptometer was used to present the preadaptation stimuli, test stimuli and record visual (luminance) thresholds of each subject. Blue/green lighting had the same affect on visual (photopic) acuity and contrast sensitivity as white and red lighting. Blue/green affected visual (absolute) threshold at the start and during the process of dark-adaptation in the same manner as white but not the same as red lighting. White and red lighting did not differ significantly (p < 0.01) at low intensities (mesopic range) but did at the higher intensities (photopic range). After exposure to blue/green and white light, it will take longer to reach the same level of dark-adaptation than after exposure to red. These time differences increase with" increased intensities. The brightness ratio between red and white lights to produce the same dark-adaptation increases with an increase in intensity. At the upper mesopic region the differences between the effects of white and red lighting on subsequent dark-adaptation become irregular due to the inability to accurately equate non-monochromatic lights in the mesopic range.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Lighting, Interior, Red, Blue, Green, White, Military applications, Image intensifiers, Photopic intensity, Visual acuity, Contrast sensitivity, Threshhold, Mesopic range, Dark adaptation|
|Subjects:||Q Science > QC Physics|
Q Science > QP Physiology
|Divisions:||Faculty > Faculty of Science > Human Kinetics & Ergonomics|
|Supervisors:||Charteris, J and Scott, P|
|Deposited By:||Philip Clarke|
|Deposited On:||10 Oct 2012 12:04|
|Last Modified:||10 Oct 2012 12:04|
0 full-text download(s) in the past 12 months
Repository Staff Only: item control page