نتایج جستجو برای: mesopic vision

تعداد نتایج: 127892  

Journal: :Journal of cataract and refractive surgery 2013
Andreia Martins Rosa Maria Fátima Loureiro Silva Conceição Lobo Joaquim Bernardes Mira Cláudia Louro Farinha João Alberto Póvoa Miguel Castelo-Branco Joaquim Neto Murta

PURPOSE To compare visual function after bilateral implantation of multifocal Lentis Mplus LS-312 (Group A) or Acrysof Restor SN6AD1 (Group B) intraocular lenses (IOLs). SETTING Ophthalmology Unit, Centro Hospitalar e Universitário de Coimbra, and Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal. DESIGN Comparative case series. METHODS P...

Journal: :Journal of refractive surgery 2009
Jens Bühren Tim Martin Anja Kühne Thomas Kohnen

PURPOSE To compare which parameter category (wavefront data, psychophysical data, or subjective symptoms) predicts best subjective quality of vision after LASIK. METHODS Twenty-eight eyes (15 patients) were included. Twenty-three eyes (12 patients) underwent uneventful LASIK; 5 eyes (3 patients) were symptomatic eyes treated with myopic LASIK elsewhere. Mean preoperative spherical equivalent ...

2010
Joel Pokorny Dingcai Cao

Mesopic light levels span approximately 3-4 log units in the natural viewing environment, including many indoor lighting settings, and most twilight or nighttime outdoor and traffic lighting environments. Traditional studies of the contribution of the different photoreceptor types to mesopic vision have been hampered by an inability to modulate the rod or cone systems independently. Our approac...

2008
Meri Viikari Aleksanteri Ekrias Marjukka Eloholma Liisa Halonen

The spectral sensitivity of the eye at low light levels, ie, mesopic conditions, is determined by the rod and cone photoreceptors of the retina operating together in varying degree as adaptation luminance shifts between the scotopic and photopic. Thus mesopic spectral sensitivity is different from photopic, where only cones contribute to vision. There are definite needs for a practical system o...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2017
Gillian L Moritz Perry S Ong George H Perry Nathaniel J Dominy

The short-wavelength sensitive (S-) opsin gene OPN1SW is pseudogenized in some nocturnal primates and retained in others, enabling dichromatic colour vision. Debate on the functional significance of this variation has focused on dark conditions, yet many nocturnal species initiate activity under dim (mesopic) light levels that can support colour vision. Tarsiers are nocturnal, twilight-active p...

Journal: :Journal of neurophysiology 2009
Incheol Kang Joseph G Malpeli

Contrast thresholds of cells in the dorsal lateral geniculate (LGNd) and medial interlaminar (MIN) nuclei of awake cats were measured for scotopic and mesopic vision with drifting sine gratings (1/8, 2, and 4 cycles/deg [cpd]; 4-Hz temporal frequency). Thresholds for mean firing rate (F0) and temporally modulated responses (F1) were derived with receiver-operating-characteristic analyses and co...

2004
MS Rea

A uni® ed system of photometry is proposed that is based on human vision and allows the speci® cation of visual stimuli at all light levels. To be useful, however, photometry can never be entirely synonymous with vision. Additivity is an essential characteristic of photometry, yet many visual responses, such as brightness matching, incorporate visual channels that are inherently non-additive in...

Journal: :Investigative ophthalmology & visual science 2016
Tina I Tsai Mirella Telles Salgueiro Barboni Balázs Vince Nagy Michel J Roux Alvaro Rendon Dora Fix Ventura Jan Kremers

Purpose The dystrophin mouse mutant mdx3Cv exhibits scotopic electroretinograpic (ERG) abnormalities, which resemble clinical changes observed in Duchenne muscular dystrophy (DMD) patients. In the present study, ERGs obtained from mdx3Cv and their wild-type littermates under scotopic, mesopic, and photopic conditions were analyzed to provide further insight on the affected retinal pathways, and...

2015
Hormoz Chams

In this presentation “A comparative study on visual and optical performance of Akreos AO and Kontur AB IOLs, after phacoemulsification cataract surgery”, Gharaee H et al have evaluated the visual performances by comparing two aspheric intraocular lenses (IOL). They indicate that with age positive spherical aberration increases, and consequently mesopic contrast sensitivity decreases and in such...

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