Quantitative and functional influence of surround luminance on the letter contrast sensitivity function

• Autores: Aparicio, Juan A.; Arranz, Isabel; Matesanz, Beatriz M.; Vizmanos, Juan G.; Padierna, Lidia; González, Víctor R.; Mar, Santiago; Menéndez, José A.; Issolio, Luis Alberto
• Año de publicación: 2010
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: CONTRAST SENSITIVITY; GLARE; PSYCHOPHYSICS; VISION
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Aim: To determine the influence of surround luminance on the letter contrast sensitivity function. Method: The binocular contrast sensitivities of 31 young and ocularly healthy individuals were measured with letters of sizes calculated to obtain the targeted fundamental frequencies of 3, 10, 20, and 30 c deg-1, respectively; with surround luminances from 1 to 1000 cd m-2, always with a test chart background luminance of 200 cd m -2. Results: The letter contrast sensitivity increased with surround luminance up to 100 cd m-2 and decreased when surround luminance increased from 100 to 1000 cd m-2. These increments are larger for higher fundamental spatial frequencies, while decrements are similar for all frequencies. To analyse pupil size influence, results were compared with theoretical predictions obtained by combining different ocular MTFs with a typical neural function, where pupil size decrease leads to letter contrast sensitivity increments and veiling luminance causes the observed decrements. Other possible optical or neural factors that influence these values have also been considered. Conclusions: Letter contrast sensitivity function depends on surround luminance and this influence should be considered in future standardized directives.
Fil: Juan Antonio Aparicio. No especifica;
Fil: Isabel Arranz. No especifica;
Fil: Beatriz Matezanz. No especifica;
Fil: Juan Vizmanos. No especifica;
Fil: L Padierna. No especifica;
Fil: V. Gonzáles. No especifica;
Fil: Juan Menéndez. No especifica;
Fil: Santiago Mar. No especifica;
Fil: Issolio, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Luminotecnia, Luz y Visión; Argentina