We describe an efficient double-filtering method that uses a single acousto-optic tunable filter (AOTF) to improve the spectral resolution and intrinsic sidelobes for the spectral domain analysis systems. Double filtering with a single AOTF is realized by applying a unique feedback scheme based on the fact that incident light can be diffracted into two orthogonally polarized beams of light by a...

BACKGROUND Maintaining functional fitness is an important problem in elderly people. Effective balance control is one of its main aspects. Evaluation and diagnosis of the weakest link in balance control (especially in this age group) facilitates appropriate prevention and rehabilitation. The goal of this study was to determine the role of the optic teleceptor and proprioception in maintaining b...

Optic flow is a key signal for heading perception. A new study has shown that the human brain can dissociate between consistent (natural) and inconsistent flow, revealing what is likely a new hierarchy in visual motion processing.

From a comparison of the results obtained by examining 'monocular' and 'stereoscopic' photographs of the optic disc it was concluded that each afforded similar levels of accuracy in identifying glaucomatous visual field defects.

Optic flow generated by rigid surface patches can be decomposed into a small number of elementary motion types. In these experiments, we show that the human visual system can evaluate expansion, one of these motion types, metrically. Moreover, we show that the discrimination of rates of expansion are spatially local. Because the estimation of the focus of expansion is somewhat imprecise, this l...

Four questions concerning the use and perception of time to contact, tc, are identified. (i) Is tc information used in the timing of interceptive actions? (ii) If so, what control strategies are used? (iii) What are the perceptual sources of tc information and which of them do people use? (iv) How is the information extracted by the perceptual systems? Research relevant to these questions is re...

Congenital aplasia and hypoplasia of the optic nerves are rarely seen in human beings4 and an imak6 Similar conditions occur infrequently in but no detailed description of the condition has been given, except for the Bmn-wys strain of rat. Bmn-wys rats are animal models of inherited retinal degeneration; aplasia or hypoplasia of the optic nerve occurs in association with microphthalmosI0 in the...