Person:
Bonnin Arias, Cristina Natalia

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First Name
Cristina Natalia
Last Name
Bonnin Arias
URI
https://hdl.handle.net/20.500.14352/79903
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
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Author: Chamorro Gutiérrez, E. × End date: 2009 ×

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    Optical filter quality effect on pupil size in night driving.
    (2009) Vinas Pena, M.; Sánchez Ramos, Celia; Chamorro Gutiérrez, E.; Bonnin Arias, Cristina Natalia
    Luminance 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.
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    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.