Search results for "Contrast Sensitivity"
showing 10 items of 115 documents
Diurnal variations in visual performance for disposable contact lenses.
2013
The purpose of this study is to compare the visual performance provided by different daily disposable contact lenses and to analyze its variation over time.Visual performance was evaluated in terms of visual acuity (VA) and contrast sensitivity (CS) in 15 myopic subjects (-0.50 to -4.00 diopters) who had been previously fitted with each one of the following seven types of soft contact lenses: DAILIES TOTAL1 (Alcon, Forth Worth, TX), DAILIES AquaComfort Plus (Alcon), 1-DAY ACUVUE TruEye (JohnsonJohnson Vision Care, Jacksonville, FL), 1-DAY ACUVUE MOIST (JohnsonJohnson Vision Care), SofLens daily disposable (BauschLomb, Rochester, NY), Proclear 1 Day (CooperVision, Fairport, NY), and Clariti …
Visual Performance of Four Simultaneous-Image Multifocal Contact Lenses Under Dim and Glare Conditions
2014
To assess and compare the effects of four simultaneous-image multifocal contact lenses (SIMCLs), and those with distant-vision-only contact lenses on visual performance in early presbyopes, under dim conditions, including the effects of induced glare.In this double-masked crossover study design, 28 presbyopic subjects aged 40 to 46 years were included. All participants were fitted with the four different SIMCLs (Air Optix Aqua Multifocal [AOAM; Alcon], PureVision Multifocal [PM; BauschLomb], Acuvue Oasys for Presbyopia [AOP; JohnsonJohnson Vision], and Biofinity Multifocal [BM; CooperVision]) and with monofocal contact lenses (Air Optix Aqua, Alcon). After 1 month of daily contact lens wear…
Diseño de una nueva prueba para medir la función de sensibilidad al contraste con iPad
2015
[EN] Purpose: To introduce a new application (ClinicCSF) to measure Contrast Sensitivity Function (CSF) with tablet devices, and to compare it against the Functional Acuity Contrast Test (FACT). Methods: A total of 42 subjects were arranged in two groups of 21 individuals. Different versions of the ClinicCSF (.v1 and .v2) were used to measure the CSF of each group with the same iPad and the results were compared with those measured with the FACT. The agreements between ClinicCSF and FACT for spatial frequencies of 3, 6, 12 and 18 cycles per degree (cpd) were represented by Bland---Altman plots. Results: Statistically significant differences in CSF of both groups were found due to the change…
Multichannel functional testing in normal subjects, glaucoma suspects, and glaucoma patients
2012
Purpose.: To evaluate visual function with a novel multichannel functional test named the ATD Multichannel Functional Test. Methods.: This multicenter study had a prospective and cross-sectional design. A total of 186 eyes were included: 42 with glaucoma, 14 glaucoma suspects due to optic nerve characteristics, 25 ocular hypertensives, and 105 normal eyes. All patients performed standard visual fields (Humphrey 24-2) and ATD with eight stimuli configurations: four achromatic (A), two red-green (T), and two blue-yellow (D). To derive main outcome measures, mean sensitivity, mean defect (MD), and pattern standard deviation (PSD) were calculated and compared among groups and types of stimuli w…
Optical quality in eyes with aspheric intraocular lenses and in younger and older adult phakic eyes: comparative study.
2009
To compare ocular higher-order aberrations (HOAs) in eyes with aspheric intraocular lenses (IOL) and in phakic eyes.Department of Ophthalmology, Military Health Service Institute, Warsaw, Poland.Higher-order aberrations with a 5.0 mm pupil and best spectacle-corrected visual acuity (BSCVA) were analyzed in a young phakic group (age 20 to 40 years), older phakic group (age 40 to 60 years), and a pseudophakic group (age 62 to 84 years; SN60WF aspheric IOL).The mean coma was 0.13 microm+/-0.07 (SD) in the younger phakic group, 0.18+/-0.08 microm in the older phakic group, and 0.16+/-0.08 microm in the pseudophakic group; the difference between the 2 phakic groups was statistically significant …
Choice of spatial frequency for contrast sensitivity evaluation after corneal refractive surgery.
2002
ABSTRACT PURPOSE: To study the utility of measurements of contrast sensitivity at different spatial frequencies as an index of visual recovery following refractive surgery. METHODS: Contrast sensitivity at 1.5, 3, 6, 12, and 18 c/deg was measured with the Stereo Optical FACT chart in 20 patients after photorefractive keratectomy (PRK) using the Nidek EC-5000 excimer laser system, and in 18 patients following laser in situ keratomileusis (LASER). Contrast sensitivity was measured preoperatively and 1, 3, 6, and 12 months after surgery. RESULTS: Results showed a statistically significant reduction (P<01) in contrast sensitivity at all spatial frequencies in PRR patients during the first an…
Differences in visual performance of AcrySof ReSTOR IOL in high and low myopic eyes.
2009
PURPOSE To determine the differences in refractive and visual results obtained in eyes with high and low myopia after multifocal intraocular lens (IOL) implantation. METHODS Monocular visual acuity for distance and near, with and without distance correction, and photopic and mesopic contrast sensitivity were measured at 6 months after surgery in 152 myopic eyes implanted with the AcrySof ReSTOR Natural (SN60D3) IOL. Two groups were created: high and low myopia (76 eyes in each). RESULTS Monocular best distance-corrected visual acuity was 0.02+/-0.06 logMAR for low myopes and 0.05+/-0.09 logMAR for high myopes. Monocular best distance-corrected near visual acuity was 0.04+/-0.05 and 0.07+/-0…
Visual quality differences between orthokeratology and LASIK to compensate low-moderate myopia.
2013
PURPOSE: To assess the differences in visual performance between orthokeratology (ortho-k) and laser in situ keratomileusis (LASIK) for the treatment of low-to-moderate myopia. METHODS: An adaptive optics visual simulator (Imagine Eyes) was used to simulate the wavefront aberration patterns induced by ortho-k and LASIK for low and moderate myopia on 10 healthy eyes. Visual acuity (VA) at 100%, 50%, and 10% contrast levels and contrast sensitivity (CS) at 10, 20 and 25 cycles per degree (cpd) were then measured for 3- and 6-mm pupil sizes. RESULTS: Differences in VA for 3-mm pupil diameter were not found between ortho-k and LASIK. For 6-mm pupil size, LASIK provided significantly better VA v…
Vision evaluation in people with Down's syndrome.
1994
We tested the colour vision of 72 people with Down's syndrome using the Ishihara test and an anomaloscope. We found that 13 of the subjects, 6 males and 7 females, had defective colour vision according to Pickford's classification. In monocular vision 10 eyes were protan (five simple, three extreme and two deviant), one eye was simple deuteranomalous and the remaining eyes were normal: in binocular vision four of the subjects were protan (two simple and two deviant), two subjects were deutan (one simple and one deviant) and the rest were normal. Many of our subjects had lens opacities, strabismus, nystagmus, hypermetropia, high myopia and astigmatism, confirming literature reports. The cont…
Symmetric bilateral implantation of a distance-dominant diffractive bifocal intraocular lens
2007
To assess visual results after symmetrical bilateral implantation of a distance-dominant bifocal diffractive intraocular lens (IOL).Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Fifty patients had bilateral implantation of a distance-dominant diffractive bifocal 447D IOL (Acri.Tec GmbH) in a prospective study. Monocular and binocular best corrected distance visual acuities and best distance-corrected near visual acuity, binocular best distance-corrected intermediate visual acuity, and distance contrast sensitivity under photopic (85 cd/m(2)) and mesopic (5 cd/m(2)) conditions were determined.At the 6-month postoperative visit, the mean binocular best corrected distance acuity and…