The ERG of the dragonfly ocellus has been analyzed into four components, two of which originate in the photoreceptor cells, two in the ocellar nerve fibers (Ruck, 1961 a). Component 1 is a sensory generator potential, component 2 a response of the receptor axons. Component 3 is an inhibitory postsynaptic potential, component 4, a discharge of afferent nerve impulses in ocellar nerve fibers. Res...

PURPOSE To continue developing a potential vision test based on the critical flicker fusion (CFF) phenomenon by using a brighter stimulus and optimizing its size. SETTING Flinders Eye Centre, Flinders Medical Centre, Flinders University, Bedford Park, South Australia, Australia. METHODS In a prospective nonrandomized study, 225 participants were assigned to 1 of 4 groups: normal, media opac...

The authors studied the relationship between the critical fusion frequency (CFF) and the threshold value of differential light sensitivity in glaucoma and retinal detachment patients. One hundred and fifty eyes of 82 glaucoma patients and 27 eyes of 27 retinal detachment patients were examined by both light-sense perimetry, using the Octopus 201, and flicker perimetry, using the Octopus 1-2-3. ...

The assessment of flicker fusion frequency (FFF), the stimulus frequency at which a flickering light stimulus can no longer be resolved and appears continuous, and critical flicker fusion frequency (CFF; the highest frequency at any light intensity that an observer can resolve flicker) are useful methods for comparing temporal resolution capabilities between animals. Behavioural experiments hav...

The photopic flicker sensitivity of the chicken was determined using an operant conditioning psychophysical technique. The results show both high- and low-frequency fall-off in the sensitivity response, which peaked around 15 Hz. Flicker sensitivity was determined for a range of stimulus luminance levels, and directly compared to human flicker response measured under similar stimulus conditions...

Amblyopia ex anopsia is characterized by a defect in visual acuity of one eye, beginning in infancy, often with strabismus. The amblyopia disappears upon occlusion of the dominant eye in children, but not readily in adults. Peripheral acuity and sensation remain normal in field and threshold studies. It is believed that the origin of the amblyopia is in the macular projection of the visual cort...

Flicker fusion threshold (F.F.T.) means the frequency with which successive flashes of light must occur to just appear to the eye free from flicker. A simple portable machine is described which will deliver flashes of light at any required interval. Patients with hypertension or anemia have a lower than normal F.F.T.; furthermore, administration of nitroglycerin, 0.4 mg. sublingually, or papave...

ABSTR^CT.--Electroretinograms were recorded from four Great Horned Owls (Bubo virginianus). Two procedures, dark adaptation and flicker stimuli, were used to assess the contributions of rod and cone systems to electroretinograms. Recordings obtained after dark adaptation demonstrated scotopic (rodgenerated) components. B-waves were broad and rounded and had a fairly long latency. When high inte...