Search results for "Color Vision"

Visual performance comparison between contact lens-based pinhole and simultaneous vision contact lenses.

2011

Background The aim was to evaluate the visual performance provided with a contact lens-based pinhole design against a simultaneous vision multifocal contact lens. Methods In a cross-over study at the University of Valencia, 22 presbyopic patients were evaluated using an artificial pupil fitted on the non-dominant eye and the simultaneous vision PureVision Multifocal contact lenses. After one month of contact lens wear, binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance contrast sensitivity, binocular near contrast sensitivity, and stereoacuity were measured, under photopic conditions (85 cd/m2). In addition, binocular distance vis…

Artificial pupil versus contralateral balanced contact lens fit for presbyopia correction.

2014

Purpose: To assess and compare the effects of contact lens-based artificial pupil design and contralateral balanced multifocal contact lens combination (CBMCLC) on visual performance. Methods: This randomized crossover study conducted at the University of Valencia, Spain included 38 presbyopic patients using an artificial pupil contact lens in the nondominant eye and a CBMCLC. After a month of lens wear, the binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance, and near contrast sensitivity and near stereoacuity (NSA) were measured under photopic conditions (85 cd/m2). Moreover, BDVA and binocular distance contrast sensitivity were …

Wavelength dependence of the optomotor response in zebrafish (Danio rerio)

2003

Abstract The action spectrum of motion detection in zebrafish (Danio rerio) was measured using the optomotor response in the light adapted state. The function has a single maximum at 550–600 nm, and is similar to the spectral sensitivity function of the L-cone type in the mid and long wavelength range. At shorter wavelengths the values of three of the five fish tested are lower. As in goldfish [Vis. Res. 36 (1996) 4025], the result indicates a dominance of the L-cone type with an inhibitory influence of M- or S-cones. Experiments with a red/green striped cylinder showed that the optomotor response was at minimum whenever the L-cone type was not modulated by the moving pattern. This demonstr…

New iPAD-based test for the detection of color vision deficiencies.

2018

Purpose: To develop and validate a new iPad-based color vision test (Optopad). Methods: A total of 341 student eyes were enrolled in a first comparative study between Optopad and the Isihara tests. In a second comparative study, Optopad vs. the Farnworth-Munsell test (FM 100H), a total of 66 adult eyes were included. Besides the agreement between tests, the correlation between FM 100H and Optopad outcomes were investigated. Multiple regression analysis was used to predict the total error score (TES) from contrast thresholds measured with the Optopad test. Results: The Ishihara and Optopad tests detected the same anomalous patients. Concerning FM 100H vs. Optopad, 10 subjects were diagnosed …

Visual quality after diffractive intraocular lens implantation in eyes with previous hyperopic laser in situ keratomileusis

2010

To evaluate distance, intermediate, and near visual quality in eyes with diffractive intraocular lens (IOL) implantation after previous hyperopic laser in situ keratomileusis (LASIK).Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Cohort study.Corrected distance visual acuity (CDVA) at 12.5%, 25.0%, and 100% contrast levels under photopic and mesopic conditions; uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuity, defocus curves, and corneal higher-order aberrations (HOAs) were measured in eyes that had AcrySof Restor SN60D3 spherical IOL implantation (study group) and in phakic eyes (control group) after hyperopic LASIK.Under photopic conditions at 100% contrast, …

Visual Function after Implantation of a Presbyopia-Correcting Trifocal Intraocular Lens

2019

<b><i>Purpose:</i></b> To evaluate distance, intermediate, and near visual performance in patients implanted with a trifocal aspheric presbyopia-correcting intraocular lens (IOL). <b><i>Methods:</i></b> Forty patients were bilaterally implanted with the AcrySofIQ PanOptix IOL after femtosecond laser-assisted lens surgery. Binocular best corrected distance visual acuity (CDVA) (4 m), best distance-corrected near visual acuity (DCNVA) (40 and 30 cm), best corrected distance intermediate visual acuity (DCIVA) (70, 60, and 50 cm), binocular distance contrast sensitivity under photopic conditions (85 cd/m<sup>2</sup>), and defocus curve…

Color memory matching in normal and red-green anomalous trichromat subjects

2001

The methods of simultaneous and successive color matching have been studied for a set of seven color reference samples by 15 protanomalous and 21 deuteranomalous trichromat subjects. From comparison between both populations and a group of 25 trichromat normal ones, investigated previously under similar experimental conditions [J. Perez–Carpinell et al. Color memory matching: time effect and other factors. Color Res Appl 1998;23:234–247], we can deduce the following. (a) For anomalous trichromat populations, as with a normal one, we find significant differences between simultaneous and successive color matching, p < 0.05. (b) If we consider the average of all the colors, we find that, while …

Electrostatic control of the photoisomerization efficiency and optical properties in visual pigments: on the role of counterion quenching.

2009

Hybrid QM(CASPT2//CASSCF/6-31G*)/MM(Amber) computations have been used to map the photoisomerization path of the retinal chromophore in Rhodopsin and explore the reasons behind the photoactivity efficiency and spectral control in the visual pigments. It is shown that while the electrostatic environment plays a central role in properly tuning the optical properties of the chromophore, it is also critical in biasing the ultrafast photochemical event: it controls the slope of the photoisomerization channel as well as the accessibility of the S(1)/S(0) crossing space triggering the ultrafast decay. The roles of the E113 counterion, the E181 residue, and the other amino acids of the protein pock…

2018

Previous studies have reported that bright ceilings appear higher than dark ceilings, irrespective of the other colorimetric properties of the ceiling color (hue, saturation) and irrespective of the luminance of the remaining room surfaces (walls, floor). In the present study, we expand these findings to width and depth estimates. We presented stereoscopic full-scale room simulations on a head-mounted display and varied the luminance of the side walls, rear wall, and ceiling independently of each other. Participants judged the width and depth of the simulated rooms. Our results show that the perceived spatial layout of a given room is significantly influenced by the luminance of the direct …

Correlation between optics quality of multifocal intraocular lenses and visual acuity

2009

Purpose To study the relationship between the optics quality of multifocal intraocular lenses (IOLs) and distance-corrected near, intermediate, and distance visual acuity to determine the degree to which optics quality must change to produce a significant difference in visual acuity. Setting Fundacion Oftalmologica del Mediterraneo, Valencia, Spain. Methods Monocular distance-corrected visual acuity (decimal and logMAR) was measured at 4 m, 70 cm, and 30 cm under photopic and mesopic conditions in eyes with 1 of 3 multifocal IOL models. Visual acuity versus the “average modulation” of the IOL was assessed. Results The pupil diameter and patient age were similar between the 3 IOL groups (20 …