This study compared the effectiveness of the ITT Night Vision Viewer with the Wide Angle Mobility Lamp (WAML) as low-vision mobility devices for people experiencing night blindness due to retinitis pigmentosa (RP). Both engineering bench testing and functional evaluations were used in the assessments. Engineering evaluations were conducted for (1) consistency of the manufacturer's specification...

In a cross-sectional survey of 5420 children in northern Bangladesh, 124 were reported to have night blindness by their parents. Of these, 105 cases along with controls matched for age, sex, and neighbourhood had their scotopic vision examined under standard condition using a luxometer, underwent an ophthalmological examination, and had their serum vitamin A level determined. The mean serum vit...

OBJECTIVE To investigate the relative frequency of the genetic causes of the Schubert-Bornschein type of congenital stationary night blindness (CSNB) and to determine the genotype-phenotype correlations in CSNB1 and CSNB2. DESIGN Clinic-based, longitudinal, multicenter study. PARTICIPANTS A total of 39 patients with CSNB1 from 29 families and 62 patients with CSNB2 from 43 families. METHO...

Anecdotal reports by pilots flying with Night Vision Goggles (NVGs) in urban environments suggest that halos produced by bright light sources impact flight performance. The current study developed a methodology to examine the impact of viewing distance on perceived halo size. This was a first step in characterizing the subtle phenomenon of halo. Observers provided absolute size estimates of hal...

INTRODUCTION The high output of night vision goggles (NVGs) can cause a loss of dark adaptation, resulting in suboptimal unaided vision. Optical filters have been designed to mitigate this problem by changing the overall output characteristics of the NVGs. METHODS Several aspects of visual performance related to NVG use were studied in a repeated measures design, filters versus no filters. NV...

An evaluation was carried out of the first prototype (LV-3) of a new night vision device, which incorporates visual field expansion through minification (Minified Augmented-View), to provide feedback for continuing development. Six subjects with night blindness completed visual function measurements and indoor mobility assessments without a device, with the LV-3 and with a commercially availabl...