retinal illuminance


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retinal illuminance 

Luminous flux incident on the retina. The simplified formula is
T = LS
where L is the luminance of the stimulus in cd/m2 and S is the area of the pupil in mm2. The retinal illuminance T is then given in trolands. Retinal illuminance decreases with age due to absorption of the lens and to a reduction in pupil size. It may represent a reduction of as much as 30 fold in an 80-year-old eye as compared to a 20-year-old eye. Syn. retinal illumination. See troland; vignetting.
References in periodicals archive ?
The source of the relationship between sensitivity to sine-wave gratings and retinal illuminance seems to require a new theoretical justification.
Modelling contrast sensitivity as a function of retinal illuminance and grating area.
5 percent decline in retinal illuminance for every year of life beyond the age of 20.
The RFTFs for rasters scanned L-R, R-L, and B-T were between 1 and 5 Hz lower than the corresponding FFF and increased in parallel to the FFFs with retinal illuminance (Figure 8).
System 1 was adjusted to give a retinal illuminance of 2.
Mean FFFs (4 participants) as a function of the retinal illuminance of the screen.
Mean RFTFs (4 participants) as a function of the retinal illuminance of the screen.
TABLE 3 Results of Two-Way ANOVA of Results for Experiment 4 Degrees of Variables Freedom F Ratio Retinal illuminance 11 285 *** Field scan direction 3 715 *** Retinal illuminance x field scan direction 33 20 *** Level of significance p < .