The high frequency of nighttime traffic accidents and the frequent complaints about glare blindness calls attention to a very important phase of highway safety investigations. Up-to-date this phase has received only meager attention by students of highway safety. There are several aspects to the night vision problem and it might be well to consider them in order. The hypothesis to be investigated may be stated as a question. What relationship exists between vision measured in daylight and vision measured in very low illumination. The Night Sight Meter is an instrument designed to give three types of scores on phases of night vision which are commonly mentioned as important to motorists travelling the highway at night. The visual measurements for daylight vision were made with the regular Sight Screener made by the American Optical Company.
Abstract