Abstract

Dark adaptation curves are obtained by presenting a 2° square test field, subdivided by vertical bars, 6° in the lateral parafovea. When pre-exposure time is constant (10 minutes), and pre-exposure brightness is progressively decreased, the cone plateau gradually drops to lower brightness levels, while the final rod level remains constant. However, when pre-exposure brightness is constant (1510 millilamberts), and pre-exposure time is varied, the cone plateau and the final rod level remain unchanged. The break in the duplex curve shifts to earlier times with decreasing pre-exposure brightness as well as with decreasing preexposure time. Linear relationships exist between time of appearance of the break (minutes) and log preexposure brightness, or log pre-exposure time. The slope constants are different, however, indicating that pre-exposure brightness and pre-exposure time are not reciprocally interchangeable as far as the location of the break is concerned.

© 1954 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
The Influence of Surround Brightness and Short Wave Components of Radiation on Dark Adaptation

Michael J. Zigler, Ernst Wolf, and Esther Shores King
J. Opt. Soc. Am. 41(5) 354-359 (1951)

Dark Adaptation Level and Duration of Testflash

Ernst Wolf and Michael J. Zigler
J. Opt. Soc. Am. 41(2) 130-133 (1951)

Studies on Dark Adaptation. II. The Pre-Exposure Tolerance of the Human Fovea Adapted to Different Brightness Levels*

Dorothea E. Johannsen, Patricia I. McBride, and Joseph W. Wulfeck
J. Opt. Soc. Am. 46(4) 266-269 (1956)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (3)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription