purpose: vision disorders are closely associated with poverty, particularly blindness. we determined the prevalence of low vision and blindness in different socioeconomic levels. our goal was determination of correlation between socioeconomic determinants and visual acuity in varamin city. methods: this community based study was done on 2737 people over the age of 50 years, living varamin city ...

background: adverse effect of sun rays mainly uv ray on the human eye documented and protection of eyes is necessary using different methods such as, sun glasses. sunglasses are designed in different colors. the aim of this study was evaluation of the effect of different colors of sunglasses on the visual acuity, contrast sensitivity, stereopsis and color vision. methods: 81 normal subjects wer...

Normal humans can match any wavelength of light with a combination of three other wavelengths. This capacity, called trichromacy, is due to the presence of three types of cone photopigment in the photoreceptors. These photopigments differ in their peak absorption at either short (S), middle (M), or long (L) wavelengths. A match between two fields of differing spectral distribution occurs when t...

The pervasive nature of computing and communications is bringing about a paradigm shift in the way these technologies are being used. The shift is in the direction of nomadic computing and communications. Nomadicity refers to the system support needed to provide a rich set of computing and communication capabilities and services to the nomad as he or she moves from place to place in a transpare...

1 Motivation: Functionality and Architecture How does the brain manage to form invariant representations of the environment that are relevant for the current behavioral task? The sensory system is steadily confronted with a massive information ow that arrives via diierent channels. In vision, spatio-temporal pattern arrangements that signal coherent surface arrangements must be somehow reliably...

Machine vision is a superior replacement for human vision in applications such as high-speed verification and testing. We review trends and issues in applying machine vision. In the last few years, machine vision systems have improved dramatically in performance, ease-of-use, intelligence, and cost. Applying machine vision to verification and testing is now relatively easy and inexpensive. Succ...