Search results for "Multifocal lenses"
showing 5 items of 5 documents
Light distortion of soft multifocal contact lenses with different pupil size and shape
2020
Purpose: To study the light distortion effects of soft multifocal contact lenses and the influence of different pupil size and shape.Methods: A total of 14 eyes of 7 healthy contact lens users (mean age 28.6 +/- 8.5 years) were recruited. The "Light Disturbance Analyser" device was employed for light characterization. The selected lenses were the monthly disposable "Biofinity multifocal" (CooperVision, CA, USA), both centre-distance and centre-near designs (addition power + 2.50 D). Two circular pupils of 3 mm and 5 mm of diameter, and an elliptical shape (3 horizontal and 5 vertical mm) were used. Metrics such as the light distortion index (LDI), best-fit circle radius and its irregularity…
Imaging Quality of Bifocal Piggyback Intraocular Lens versus ReSTOR and TECNIS Multifocal Lenses
2009
Purpose The imaging quality provided by a piggyback integrated by a monofocal intraocular lens (IOL) + a bifocal IOL of zero power and +3.75 diopters of addition is compared with the optics quality of a simple multifocal IOL of the same power and addition. Methods The imaging quality was evaluated by determining the modulation transfer function (MTF), using an artificial eye simulating in vivo conditions of the anterior chamber, including an artificial cornea and a wet cell containing physiologic solution where the IOL was positioned. The MTFs of the bifocal piggyback for near and distance vision were measured, with pupil diameters of 3 and 5 mm, and compared with the MTFs of an equivalent …
Stereoacuity with simultaneous vision multifocal contact lenses.
2010
Our purpose was to evaluate near stereoacuity (SA) with Focus Progressives and PureVision Multifocal simultaneous vision contact lenses. In a cross-over study design, 20 presbyopic subjects were fitted with either the Focus Progressives or PureVision Multifocal lenses. After 1 month, SA was measured with the vectographic Titmus, Random dot stereotests, and the Howard-Dolman apparatus under photopic conditions (85 lux) at 40 cm. Binocular high-contrast visual acuity at distance and near was examined. Subjects were then refitted with the alternative correction and the procedure was repeated. Mean SA with the Focus Progressive was 21 +/- 7 sec arc, 54 +/- 17 sec arc, and 51 +/- 21 sec arc, wit…
Imaging quality of multifocal intraocular lenses: automated assessment setup
2012
[EN] Purpose: A new technique for the assessment of the optical quality of multifocal intraocular lenses (MIOLs) under monochromatic and polychromatic illumination is presented. Methods: The system provides, in a totally automated procedure, the modulation transfer function (MTF) of the lens under test for different axial positions of the object. The artificial eye admits different artificial corneas, to optimise the axial resolution in the sampling of the MTF of the MIOL under test, and different pupils, to test the dependence of the optical performance of the MIOL on the eye pupil diameter. Results: The performance and sensitivity of the apparatus is tested with different commercial MIOLs…
Diffractive multifocal intraocular lenses: reading performance and quality of life evaluation
2011
ABSTRACT Purpose: To evaluate the reading performance and changes in quality of life after cataract surgery with multifocal diffractive (IOLs) implantation Setting: Section of Ophthalmology - Department of Experimental Biomedicine and Clinical Neuroscience, University of Palermo, Italy; Eye Clinic - Department of Preclinical and Clinical Pharmacology, University of Florence, Italy. Methods: 160 Consecutive eyes of cataract patients were divided into two groups. One group (20 patients, 40 eyes) received aspheric monofocal IOLs (Acrysof SN60WF). One group (60 patients, 120 eyes) was implanted with a diffractive aspheric multifocal IOL produced by different manufacturers: 20 patients with Acry…