scholarly journals “Emmetropic, but not myopic human eyes distinguish positive defocus from calculated defocus in monochromatic red light”

2022 ◽  
Vol 192 ◽  
pp. 107974
Author(s):  
Barbara Swiatczak ◽  
Frank Schaeffel
Keyword(s):  
Author(s):  
Fred V. Brock ◽  
Scott J. Richardson

Visibility measurement is the most human-oriented measurement discussed because the objective of such measurement is to determine the distance at which humans (pilots, seamen, etc.) can see objects. Thus we are concerned with light that can be seen by humans (0.4 to 0.7μm), the way human eyes perceive such light, and then with the transparency of the atmosphere. Throughout this chapter, in the discussion of atmospheric transparency or absorption, the range of wavelengths from 0.4 (violet) to 0.7μm (red light) will be assumed. Cloud height is a remote sensing measurement but is included here because airport meteorological systems usually include a cloud height sensor. According to the WMO, meteorological visibility by day is defined as the greatest distance that a black object of suitable dimensions, situated near the ground, can be seen and recognized when observed against a background of fog, sky, etc. Visibility at night is defined as the greatest distance at which lights of moderate intensity can be seen and identified.


Reproduction ◽  
2000 ◽  
pp. 327-330 ◽  
Author(s):  
RJ Lucas ◽  
JA Stirland ◽  
YN Mohammad ◽  
AS Loudon

The role of the circadian clock in the reproductive development of Syrian hamsters (Mesocricetus auratus was examined in wild type and circadian tau mutant hamsters reared from birth to 26 weeks of age under constant dim red light. Testis diameter and body weights were determined at weekly intervals in male hamsters from 4 weeks of age. In both genotypes, testicular development, subsequent regression and recrudescence exhibited a similar time course. The age at which animals displayed reproductive photosensitivity, as exhibited by testicular regression, was unrelated to circadian genotype (mean +/- SEM: 54 +/- 3 days for wild type and 59 +/- 5 days for tau mutants). In contrast, our studies revealed a significant impact of the mutation on somatic growth, such that tau mutants weighed 18% less than wild types at the end of the experiment. Our study reveals that the juvenile onset of reproductive photoperiodism in Syrian hamsters is not timed by the circadian system.


1999 ◽  
Vol 69 (3) ◽  
pp. 353 ◽  
Author(s):  
Anne C. E. Moor ◽  
Angeline E. Wagenaars-van Gompel ◽  
Ralph C. A. Hermanns ◽  
Jannes van der Meulen ◽  
Jolanda Smit ◽  
...  

2020 ◽  
Vol 2020 (15) ◽  
pp. 197-1-197-7
Author(s):  
Alastair Reed ◽  
Vlado Kitanovski ◽  
Kristyn Falkenstern ◽  
Marius Pedersen

Spot colors are widely used in the food packaging industry. We wish to add a watermark signal within a spot color that is readable by a Point Of Sale (POS) barcode scanner which typically has red illumination. Some spot colors such as blue, black and green reflect very little red light and are difficult to modulate with a watermark at low visibility to a human observer. The visibility measurements that have been made with the Digimarc watermark enables the selection of a complementary color to the base color which can be detected by a POS barcode scanner but is imperceptible at normal viewing distance.


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