Reciprocity of Intensity and Duration on the Dark Adaptation Effects of Light Pulses

Abstract

Public reporting burden for this collection of information is estimated lo average 1 hour per response, including the lime for reviewing instructions, searching existng data sources, gathenng and ™ n a n,ng he data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspeco this collection of ,nforTOt,on_,nclud,ngs^geston^; for reducing this burden to Department oFDefense. Washington Headquarters Services. Directorate for Information . 1215 Jefferson Davis Highway. Su.te 204, Ahington.VA 22202-4302 Respondents should be aware that notwithstanding any other provision of law. no person shall be subject to any penalty for failing to comply with a collect«» of information ,f ,t does not display a currently valid OMB control number PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. . REPORT DATE (DD-MM-YYYY)November 2002 2. REPORT TYPE Final TITLE AND SUBTITLE Reciprocity of Intensity and Duration on the Dark Adaptation Effects of Light Pulses AUTHOR(S)William Kosnik PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)Northrop Grumman Information Technology 4241 Woodcock Drive, Suite B100 San Antonio, TX 78228 SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)Air SPONSOR/MONITOR'S ACRONYM(S)AFRL/HEDO SPONSOR/MONITOR'S REPORT NUMBER(S) AFRL-HE-BR-TR-2 002-0107 DISTRIBUTION / AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTThis report addressed two questions. First, over what durations and intensities do light exposure of equal energy appear equally bright? Second, do light exposures of equal energy have equivalent effects on the course of dark adaptation? These questions were addressed to refine the AFRL/HEDO flashblindness model. These studies show that reciprocity between duration and intensity is the exception rather than the rule for dark adaptation. The evidence indicates that reciprocity can be expected from about 100 ms to about 10 ms. A study linking a range of short duration exposures from nanoseconds to milliseconds is lacking. During the initial stage of dark adaptation, different duration exposures have very different initial thresholds and recovery functions. From the standpoint of modeling, for exposure durations less than 10 ms, dark adaptation could be described by a single dark adaptation function. Modern lasers now make it possible to study very short duration exposures. SUBJECT TERMS