Person: Bonnin Arias, Cristina Natalia
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First Name
Cristina Natalia
Last Name
Bonnin Arias
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Optical filter quality effect on pupil size in night driving.(2009) Vinas Pena, M.; Sánchez Ramos, Celia; Chamorro Gutiérrez, E.; Bonnin Arias, Cristina NataliaLuminance conditions during driving vary tremendously, with, in some cases, abrupt differences between areas of intense and poor illumination, depending on the daytime, the weather, vehicle headlights and the environmental illumination, among others. This affects to the driver´s visual system, which is able to adapt itself to these different luminances by varyting its pupil size. There is little doubt that the most important and best-studied afferent visual signal that drives the pupil is generated by changing the ambient illumination. The accepted clinical view of the pupil response to light is that the ambient light level determines largely the steady state size of the pupil and that rapid increments in light flux on the retina cause a brisk constriction of the pupil, that is often described as the dynamic pupil light relfex response. The pupil response to changes in ambient illumination is best served by neural mechanisms that respond to overall light flux changes, cover a large dynamic range and exhibit large spatial summation. Pupillary response to light measures the integrity of neuronal pathways goberning pupil size. The oculomotor nerve is the efferent link and the optic nerve is the afferent link. The mechanisms controlling the pupillary constriction and dilation have been explained by Barbur (2004) and Lowenfeld (1993). Briefly, a large pupil diameter reduces distortion due to light diffraction and dispersion and allow more light to reach the retina. Conversely, by limiting the entry of light rays, a small pupil increases the depth of focus and reduces chromatic and spherical aberrations.Item Wetability and deposits accomulation on anterior surface of blue light-filtering contact lens.(2012) Chamorro Gutiérrez, E.; Bonnin Arias, Cristina Natalia; Ramirez Mercado, G.; Urbano Rodríguez, R.; Ríos Santos, R.; Sánchez Ramos, CeliaPurpose: To evaluate wetability and deposits accumulation on anterior surface of blue light-fi ltering contact lens after a cleaning process with Multi-purpose Solution Cleaning, Hydrogen Peroxide solution and Lubricant Drops. Methods: A self-controlled trial was carried out in 41 contact lens users who were wearing blue light-fi ltering contact lens (Profi lcon A 52%WC) for 30 minutes per test. Wetability and deposits accumulation on anterior surface were evaluated according to the International Organization for Standardization ISO11980 guidelines. Four conditions were set: a)usual contact lens, b)blue light-fi ltering contact lens after cleaning process with Multi-purpose Solution Cleaning, c)after Hydrogen Peroxide solution disinfection and d) after Lubricant Drops instillation. Results: Statistically signifi cant diff erences were not observed within the parameters evaluated among the diff erent cleaning solutions proposed. For a,b,c and d conditions, the percentage of lens that showed very insignifi cant deposits accumulation(visible after drying tear fi lm) were 25%,34%,20% and 27%, respectively and the percentage of lens that showed not signifi cant deposits (deposits easily eliminated) were 3%,2%,7% and 8%, respectively. Regarding wetability, minor wetability problems were showed and these ones were solved by the blinking in 18%, 29%, 18% and 18% of the cases, respectively, whereas the areas that remained dry on the contact lenses were 4%,0%,5% and 2% of the cases. Conclusion: wetability and deposits accumulation on anterior surface of blue light filtering contact lenses is similar for the diff erent cleaning treatment and equivalent to the non blue light-fi ltering contact lens.Item Changes in contrast sensitivity perception due to protector screens for welding tasks : conventional protective optical filter vs novel protective optical filter of selective absorbance(2012) Bonnin Arias, Cristina Natalia; Aguirre Vilacoro, V.; Chamorro Gutiérrez, E.; Lobato Rincón, Luis Lucio; Langa Moraga, Antonio; Navarro Valls, J.J.; Sánchez Ramos, CeliaPurpose: To evaluate diff erences in contrast sensitivity perception in central visual field using protective optic fi lters for welding tasks. Two interposed filters are compared: a conventional protective optical fi lter and a new protective optical fi lter with selective absorption designed by University Complutense of Madrid (UCM). Methods: 36 people of working-age were included in a cross-sectional prospective observational study. Contrast sensitivity threshold in central visual fi eld was evaluated using FDT Perimeter, C-20 procedure (Humphrey systems, USA). ! ree conditions were set: a) without optical fi lters; b) with an interposition of conventional protective optical fi lter for welding (shade 2.5) and c) with an interposition of a novel protective optical fi lter of selective absorbance that fully blocks the short wavelength light and minimally attenuates the remaining bands of the visible spectrum. Results: Contrast sensitivity in all visual fi eld areas evaluated diminished 91-98% with the conventional protective optical fi lters. UCM optical fi lters provoked a low-level decrease in contrast sensitivity (9-19%). Mean contrast sensitivity thresholds were 29.5±5dB, 25.5±4dB, 1.8±2dB in conditions a, b and c respectively Conclusion: Conventional optical fi lters resulted in drastically diminished contrast sensitivity. UCM optical fi lter minimally diminish the visual function, allowing a suitable visibility and also maintaining an appropriate level of protection against phototoxic damage.Item Variation of mesopic and photopic spatial resolution in drivers older than 65 years old.(2009) Sánchez Ramos, Celia; Bonnin Arias, Cristina Natalia; García García, R.; Vinas Pena, M.; Chamorro Gutiérrez, E.; Gómez Tortuero, E.In the last century, the proportion of people over the age of 65 years has tripled (Haegerstrom-Portnoy, 1999). According to the US census 2000, persons over 65 years of age comprised 12.4% of the inhabitants of the United States (Schwager, 1999). The spanish National Institute of Statistics estimated this proportion at 16.8% of the population of Spain in 2009, representing a growth rate far higher than shown by other age groups (INE, 2009). Besides this increase, the number of elderly people who continue to drive is set to show a spectacular rise after 2010, due to the incorporation of the "baby-boom" generation and the considerably greater number of women drivers. Added to this social changes and the improved health of the elderly subject are raising the mean age of drivers (Hakkinen, 1984). Spherical and astigmatic defects worsen with age, negatively affecting visual acuity and sensitivity to contrast and glare. Ageing is also associated with diminised myopia, increased hyperopic and tendency towards inverse astigmatism (Adams, 1988). In addition, the retina often undergoes macular degeneration (Morgan, 1986). The physiological alterations of ageing also lead to changes in our sensitivity to light. Enhanced light scattering in the eye gives rise to glare, a decreased pupil diameter with the consequent reduced retinal illumination and to a general decline in visual perception (Van Den Ber, 1986). The present investigation was designed to evaluate the refractive error in vehicle drivers over the age of 65 years and to determine the possible effects of improving their habitual optical correction on visual acuity.Item Acid-Sensing ion channels 2 and 4 (Asic 2 Saic 4) are regulated by light in the zebrafish retina(2012) Sánchez Ramos, Celia; Germaná, A.; Bonnin Arias, Cristina Natalia; Chamorro Gutiérrez, E.; Navarro Valls, J.J.; García Ortega, M.; Pérez Carrasco, María Jesús; Vega, J.A.Purpose: Acid-sensing ion channels (ASICs) are H+- gated cation channels that monitor deviations from the physiological values of extracellular pH. ASIC genes in zebrafish (zASICs) are expressed in the central nervous system and the retina. pH variations in the retina are thought to be involved in the fine-tunning of visual perception and in the adaptation of the retinal responses to different light-induced retinal degeneration. This study examines the effects of continuous light or darkness exposure in the mRNA levels and cell distribution of ASIC2 and ASIC4 in the retina of adult zebrafish.