Most vertebrates have a duplex retina comprising two photoreceptor types, rods for dim-light (scotopic) vision and cones for bright-light (photopic) and color vision. However, deep-sea fishes are only active in dim-light conditions; hence, most species have lost their cones in favor of a simplex retina composed exclusively of rods. Although the pearlsides, Maurolicus spp., have such a pure rod ...

Purpose. Our aim was to compare contrast sensitivity values of the dominant and nondominant eyes of healthy middle-aged subjects. Material and Methods. Ninety eyes of 45 healthy middle-aged subjects (30 males and 15 females) were included in this study. Patients were aged between 40 and 60 years, having uncorrected visual acuity (UCVA) of 20/25 or better (Snellen chart). Ocular dominance was de...

Cone vision has been shown to be temporally inhomogeneous across the visual field. In the periphery, contrast sensitivity is lower for low temporal frequencies and higher for high temporal frequencies. Here we ask a similar question for rod vision at mesopic luminances. Isolation is obtained by testing a well documented rod monochromat. We show that the rod visual field exhibits only a modest d...

AIM To investigate the independent factors associated with photic phenomena in patients implanted with refractive, rotationally asymmetric, multifocal intraocular lenses (MIOLs). METHODS Thirty-four eyes of 34 patients who underwent unilateral cataract surgery, followed by implantation of rotationally asymmetric MIOLs were included. Distance and near visual acuity outcomes, intraocular aberra...

METHODS: Patients with senile monocular cataract were randomly assigned to receive either a blue light-filtering aspheric IOL (Aspira-aAY group), its clear aspheric counterpart (Aspira-aA group) or the clear spherical model (AS group). The primary outcome measures were visual acuity for distance, intermediate (1 m), near (40 cm), contrast sensitivity under photopic (85 cd2) and mesopic (3 cd2) ...

PURPOSE To evaluate whether the Tecnis Z9000 intraocular lens (IOL) (Pfizer) with a modified prolate anterior surface provides better quality of vision than a conventional spherical IOL. SETTING Oregon Eye Institute, Eugene, Oregon, USA. METHODS Patients presenting for cataract surgery who were randomly assigned to receive a Tecnis Z9000 IOL (Pfizer) or a Sensar OptiEdge AR40e IOL (AMO) in ...

PURPOSE To determine the relationship between the size of a halo induced by a glare source and forward scatter or visual acuity (VA) in healthy eyes. METHOD Measurements were made in the right eyes of 51 healthy individuals of mean age 29.3 ± 7.5 years. Halo radius was measured using the Vision Monitor and low luminance (1 cd/m(2)) optotypes presented at a distance of 2.5 m. The visual angle ...

The sensitivity of the human eye varies with different lighting conditions to which it is exposed. cone photoreceptors perceive color and work for illuminance greater than 3.00 cd/m² (photopic vision). Below 0.01 cd/m², rods are cells that assume this function (scotopic Both types coordinately in interval between these values (mesopic Each mechanism generates a spectral sensibility. In work, em...

PURPOSE To compare the contrast sensitivity of an intraocular lens (IOL) with a modified prolate anterior surface (Tecnis Z9000, Pfizer), with 2 standard spherical IOLs (Sensar AR40e Opti-Edge IOL, AMO and AcrySof Natural SN60AT IOL, Alcon). METHODS In this prospective study, 98 eyes of 71 patients received 1 of 3 IOLs at random. After 6 months, best corrected visual acuity, pupil size and co...