A bias in heading estimation is observed if an extraneous object moves so as to obscure the focus of expansion of an optic flow field generated by linear translation. This bias, however, has only been shown for simple, non-articulated objects with no social or behavioural relevance. Contrastingly, objects in the real world are often much more complex and can be comprised of multiple, differentl...

We measured perceived depth from the optic flow (a) when showing a stationary physical or virtual object to observers who moved their head at a normal or slower speed, and (b) when simulating the same optic flow on a computer and presenting it to stationary observers. Our results show that perceived surface slant is systematically distorted, for both the active and the passive viewing of physic...

PURPOSE To examine the roles of genetic and environmental factors in the optic disc in a classic twin study. METHODS Five hundred six pairs of twins were recruited to participate from the Twins U.K. Adult Twin Registry at St. Thomas' Hospital, London. Photographs of the optic disc were obtained, and the covariance of optic disc, cup, and rim areas within monozygotic (MZ) and dizygotic (DZ) pa...

Examination of stereoscopic optic disc photographs allowed accurate prediction of glaucomatous and normal fields to be made in 82 and 95% of eyes respectively and for visual field loss to be correctly located in upper and lower half in 83 and 91% of cases respectively. Despite this high correlation the existence of false positive and fale negative predictions means that the total reliance on op...

PURPOSE To compare the measurements of the optic nerve head (ONH) parameters provided by time-domain (TD) and spectral-domain (SD) optical coherence tomography (OCT). METHODS Four ONH parameters were analyzed: optic disc area, rim area, cup-to-disc area ratio (CDR), and vertical cup-to-disc ratio (VCDR). Stratus OCT and Cirrus HD-OCT were used to obtain measurements by TD-OCT and SD-OCT, resp...

A case is reported in which recurrent episodes of visual loss occurred over a period of 26 years in a patient with bilateral optic disc drusen. Visual field loss was associated with episodes of ischaemic optic neuropathy. The possible mechanism is discussed.

Optic nerve formation in mouse involves interactions between netrin-1 at the optic disk and the netrin-1 receptor DCC (deleted in colorectal cancer) expressed on retinal ganglion cell (RGC) axons. Deficiency in either protein causes RGC pathfinding defects at the disk leading to optic nerve hypoplasia (). Here we show that further along the visual pathway, RGC axons in netrin-1- or DCC-deficien...

AIMS/BACKGROUND It has been reported that the number of optic nerve fibres decrease with age, and the cup/disc (C/D) ratio increases as the optic disc size increases. Consequently, the normal value of the optic disc variables measured by an optic disc analyser may change according to the optic disc size or age. The effect of individual variations in optic disc size or age on interpretation of o...