In this paper, we present a novel tone reproduction operator that is able to handle the color shift that occurs in photopic, mesopic, and scotopic vision, using a model based on a two-stage model of human color vision and psychophysical data obtained from measurements of human color perception. Since conventional methods are limited to generating images under a certain visual condition, it is d...

We studied the effect of rod-cone interactions on mesopic visual reaction time (RT). Rod and cone photoreceptor excitations were independently controlled using a four-primary photostimulator. It was observed that (1) lateral rod-cone interactions increase the cone-mediated RTs; (2) the rod-cone interactions are strongest when rod sensitivity is maximal in a dark surround, but weaker with increa...

PURPOSE To evaluate the 12-month U.S. phase II clinical trial results of the Crystalens AT-45 (eyeonics, Inc.) intraocular lens (IOL) used to provide uncorrected distance, intermediate, and near visual acuities in patients having cataract extraction and to compare in a substudy the contrast sensitivity and near visual acuity in patients with the Crystalens AT-45 IOL and those receiving a standa...

AIM To determine the agreement and repeatability of the pupil measurement obtained with VIP-200 (Neuroptics), PowerRef II (Plusoptix), WAM-5500 (Grand Seiko) and study the effects of instrument design on pupillometry. METHODS Forty patients were measured twice in low, mid and high mesopic. Repeatability was analyzed with the within-subject standard deviation (Sw) and paired t-tests. Agreement...

PURPOSE To determine whether the difference in optic quality between 2 types of phakic intraocular lenses (pIOLs) affects visual quality. SETTING Fundación Oftalmológica del Mediterráneo, Valencia, Spain. METHODS Before implantation of a pIOL for myopia, all eyes had an examination including corrected (CDVA) and uncorrected (UDVA) distance visual acuity testing, corneal endothelial cell cou...

Due to heterogeneous photoreceptor distribution, spatial location of stimulation is crucial to study visual brain activity in different light environments. This unexplored issue was studied through occipital event-related potentials (ERPs) recorded from 40 participants in response to discrete visual stimuli presented at different locations and in two environmental light conditions, low mesopic ...

PURPOSE To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL) on contrast sensitivity and blue-on-yellow perimetry. METHODS This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes) received aspherical intraocular lens in one eye and spher...

PURPOSE To evaluate whether implantation of an aspheric intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery and, therefore, changes on frequency-doubling technology (FDT) testing. METHODS The present prospective clinical study enrolled 25 patients with bilateral cataract (50 eyes), who randomly received either an aspheric (Akre...

We determined how rod signaling at mesopic light levels is altered by extrinsic temporal white noise that is correlated or uncorrelated with the activity of one (magnocellular, parvocellular, or koniocellular) postreceptoral pathway. Rod and cone photoreceptor excitations were independently controlled using a four-primary photostimulator. Psychometric (Weibull) functions were measured for incre...