Person:
Pérez Carrasco, María Jesús

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First Name
María Jesús
Last Name
Pérez Carrasco
URI
https://hdl.handle.net/20.500.14352/79893
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
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End date: 2003 × Start date: 2003 × Item Type: Publication ×

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Now showing 1 - 3 of 3
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    Effect of a yellow filter on mesopic contrast perception and differential light sensitivity in the visual field.
    (Ophthalmic Research, 2003) Pérez Carrasco, María Jesús; Puell Marín, María Cinta; Sánchez Ramos, Celia; Langa Moraga, Antonio
    Purpose: Previous studies on the effects of yellow filters in the visual performance have been carried out, presenting discrepancies among the different investigations. Our study reports the influence of the yellow filter without residual reflections on contrast perception and differential light sensitivity (DLS) under mesopic conditions. Methods: Contrast sensitivity, low contrast visual acuity and luminance thresholds in the central visual field (30 degrees ) were measured in a group of 38 adult subjects with and without a coated yellow lens (482-nm cut-off) under mesopic conditions. Results: The contrast sensitivity mean was significantly better with the filter at low- and middle-range spatial frequencies (1.5 cycles/degree p = 0.002 and 6 cycles/degree p = 0.02). At 5% contrast, the mesopic low contrast visual acuity improved significantly (p = 0.004) when interposing the yellow filter. The increase in DLS was statistically significant [e.g. all visual fields p = 0.0003 and macular visual field (9.5 degrees ) p = 0.00001] through the yellow filter on the different established areas of the visual field (30 degrees ). Conclusions: The yellow filter without residual reflections had a positive influence on the brightness and contrast perception of healthy subjects, for which its use would be beneficial under mesopic conditions.
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    Nuevo instrumento para medir la sensibilidad al contraste sin y con deslumbramiento
    (Archivos de la Sociedad Española de Oftalmología, 2003) Sánchez Ramos, Celia; Puell Marín, María Cinta; Pérez Carrasco, María Jesús; Langa Moraga, Antonio; Benítez Del Castillo Sánchez, José Manuel
    OBJETIVO/MÉTODO: valorar la sensibilidad al contraste fotópica, sin y con deslumbramiento con un nuevo instrumento. Se estudiaron 78 ojos derechos de 49 adultos jóvenes y de 29 adultos entre 35 y 55 años. La sensibilidad al contraste se midió con el Contrast Glarester CGT-1000 mediante una estrategia automatizada de reconocimiento para seis frecuencias espaciales. RESULTADOS/CONCLUSIONES: Los valores de sensibilidad al contraste fueron semejantes a los obtenidos con otros test clínicos. El aumento de la edad disminuyó significativamente la sensibilidad al contraste sin y con deslumbramiento. Sin embargo, el deslumbramiento no modificó la sensibilidad al contraste fotópica.
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    Mesopic contrast sensitivity and glare disability in drivers.
    (2003) Sánchez Ramos, Celia; Puell Marín, María Cinta; Pérez Carrasco, María Jesús; Langa Moraga, Antonio; Benítez Del Castillo Sánchez, José Manuel
    Visual Acuity is a poor predictor of driving ability and it is likely to be a poor predictor of many aspects of real-world vision, because the real world is not composed purely of fine objects with sharp edges at high contrast. Although not all objects are at contrst treshold either, it has been shown that a loss of contrast sensitivity (CS) is roughly equivalent to a loss of image contrast in the normal eye (OWSLEY, 1994). The extent of contrast loss required before real-world performance is reduced depends on the real-world task being performed. Somo tasks, such as optimal speed reading and mobility orientation in a well-llit room, tolerate large reductions in contrast (Elliot, 1996; Leffe, 1993; Pelli, 1986). These tasks would probably only be affected in patients with a severe loss of contrast sensitivity. However, other tasks such as speed reading newspaper-size print and face recognition are moderately affected by contrast reduction (Elliot, 1996). Further, mobility orientation under dim illumination has been shown to be seriously affected by reduced contrast. Thus, under low-iluminance conditions and when a subject is working near his or her acuity limit, tolerance to contrast loss is reduced (Legge, 1993)