AIMS To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes. METHODS To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal...

Stereo vision is a resource-intensive process. Nevertheless, it has evolved in many animals including mammals, birds, amphibians and insects. It must therefore convey significant fitness benefits. It is often assumed that the main benefit is improved accuracy of depth judgments, but camouflage breaking may be as important, particularly in predatory animals. In humans, for the last 150 years, st...

PURPOSE The author reports the results of visual and binocular tests performed on patients who had primary insertion of intraocular lenses following the removal of cataracts in their childhood. METHODS Monocular and binocular tests were performed on 21 patients using the same equipment for sensory testing for binocularity on all patients before the history was abstracted from the clinical rec...

Neurons in the early visual cortex are finely tuned to different low-level visual features, forming a multi-channel system analysing the visual image formed on the retina in a parallel manner. However, little is known about the potential 'cross-talk' among these channels. Here, we systematically investigated whether stereoacuity, over a large range of target spatial frequencies, can be enhanced...

PURPOSE This study was designed to evaluate the minimum interocular correlation (IOC) needed by the visual system to correctly perceive a static stereoscopic stimulus as a function of normal aging. It was also our goal to evaluate the feasibility of clinical charts testing this aspect of visual perception. METHODS Stereoscopic IOC threshold was determined in 100 normal observers (average age ...

BACKGROUND The critical period during which the dietary supply of long-chain polyunsaturated fatty acids (LCPs) may influence the maturation of cortical function in term infants is unknown. OBJECTIVE The aim of the present study was to determine the relative importance for maturation of the visual cortex of the dietary supply of LCPs during the first 6 wk of life compared with that during wee...