Results: As expected, both groups showed deficits in monocular acuity, with subjects with strabismus showing greater deficits in Vernier acuity. Both amblyopic groups were then characterized according to the degree of residual stereoacuity and binocular motion integration ability, and 67% of subjects with strabismus compared with 29% of subjects with anisometropia were classified as having “non...

Neural changes that result from disruption of normal visual experience during development are termed amblyopia. To characterize visual deficits specific to astigmatism-related amblyopia, we compared best-corrected visual performance in 330 astigmatic and 475 non-astigmatic kindergarten through 6th grade children. Astigmatism was associated with deficits in letter, grating and vernier acuity, hi...

Foveal discrimination thresholds were measured for orientation, vernier alignment, bisection, displacement detection and stereoscopic acuity using simple line stimuli and also sinusoidal grating patches with gaussian intensity modulation (Gabor stimuli). Stimulus parameters such as luminance, exposure duration, component separation and, as far as possible, length were identical for both. Orient...

Humans can discriminate among elementary features such as orientation, color, and depth in parallel. The author showed that discontinuities in lines, such as a vernier offset, can be detected in a flash presentation with subsequent mask, and an offset, even below the diameter of foveal photoreceptors, is identified among distractors. This result suggests that the visual system simultaneously de...

Stereoacuity improves with increasing contrast, unless the increase is monocular. In this case performance paradoxically suffers. This study examined whether this contrast paradox occurs for two other classes of visual judgment: two-frame motion and vernier acuity. We constructed three homologous tasks in which the two components of a gabor stimulus (stereo half-images, motion frames, vernier c...

A highly sensitive refractive index (RI) sensor based on two cascaded microfiber knots with vernier effect is proposed and demonstrated by theoretical arithmetic. Deriving from high proportional evanescent field of microfiber and sharp spectrum fringes induced by vernier effect, a slight change of ambient RI will cause large variation of effective RI and significant wavelength shift of resonant...

Vernier acuity for short horizontal, vertical and oblique target lines was measured in many locations in the periphery of the visual field in normal human observers. In the 10 deg periphery, the average alignment threshold with oblique vernier lines in eight locations for three observers was 2.29 times higher than that with vertical and horizontal target lines. This oblique effect was found eve...