Night vision

About: Night vision is a research topic. Over the lifetime, 6004 publications have been published within this topic receiving 67372 citations.

Scotopic electrophysiology of the retina during transient hyperglycemia in type 2 diabetes.

Abstract: PURPOSE: To examine dark-adapted retinal function in subjects with type 2 diabetes during transient hyperglycemia. METHODS: Twenty-four subjects with type 2 diabetes and minimal diabetic retinopathy were randomized to an oral glucose tolerance test (OGTT) or a fasting regimen. One study eye was kept in the dark-adapted state at all times. Full-field electroretinography (ffERG) and blood glucose measurements were performed at baseline and after 20, 80, 140, and 200 minutes. RESULTS: Mean capillary glucose had increased 162% from the fasting baseline value when the concentration peaked in the OGTT group after 80 minutes (P < 0.0001). Concomitantly, rod b-wave amplitude had increased by 34% (P = 0.0007), whereas the a- and b-wave amplitudes of the standard combined rod-cone response had increased by 17% (P = 0.0013 and P = 0.0064). The dark-adapted 30-Hz flicker response was unaffected by hyperglycemia. The scotopic ffERG amplitudes rose and fell in phase with the glycemia. Implicit times did not change with the rise and fall in glycemia. CONCLUSIONS: The change in scotopic signaling amplitude in the outer and middle layers of retina in subjects with diabetes was proportional to the change in capillary glucose. Cone amplitude was not influenced by hyperglycemia in this study.

Driver search and scan patterns in night driving

Abstract: Because the rates of nighttime accidents are higher than daytime accidents, much research has been directed to the unique problems of night driving. Many researchers concur that the driver receives most of his or her information through the visual system. During night driving, the visual cues normally available during daytime are reduced. Whether this paucity of visual information is related to the higher night accident rate is not known. A basic approach to the problem is to identify through visual search patterns the driver's use of night driving cues. Identification of driver visual needs in night driving can eventually lead to improved night driving safety. This paper discusses and presents the results of two studies to investigate drivers' visual search patterns in night driving. The first study compares nighttime visual search behavior to daytime behavior on freeways and rural highways. The second study develops methods of using driver visual search data to evaluate illumination at rural highway intersections, which have high rates of nighttime accidents.

Interactions among light source luminance, illuminance and size on discomfort glare

Abstract: Discomfort glare from vehicle lighting is more difficult to measure precisely than disability glare, but may have important implications for driver behavior, and in turn on driving safety. Many studies of discomfort glare have found that, as with disability glare, the illuminance at the eyes from a bright light is the primary determinant of the sensation of glare. Nonetheless, the luminance of a light source also can influence discomfort glare, especially when the source is close enough to subtend a relatively large visual angle on the order of a third of a degree or larger. In addition, interactions with the absolute illuminance from a light source are not well understood. The results of an experimental investigation of discomfort glare in terms of light source illuminance, luminance and size are presented and discussed along with implications for automotive lighting applications. Language: en

Review Lecture Electronic Aids to Night Vision

Abstract: The human eye is a very sensitive and versatile image detector, but has a number of physical limitations The most important of these at very low light levels is the restriction in sensitivity resulting from the statistical fluctuations in the numbers of detected photons It is shown how electronic image intensifies can provide a fundamental improvement in this situation by capturing a larger fraction of the available photons and using these more efficiently The important parameters of such instruments are discussed, together with the principles of operation of their most significant component: the image intensifier tube This is followed by a more detailed discussion of the possible performance of night vision equipments based on different types of tube, both for direct and remote viewing applications