ILAV   21219
INSTITUTO DE INVESTIGACION EN LUZ, AMBIENTE Y VISION
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effects of refractive corrections on contrast sensitivity under mesopic conditions
Autor/es:
DE PAUL, ANÍBAL; ISSOLIO, LUIS A.; COMASTRI, SILVIA ANA; APARICIO, JUAN ANTONIO; COLOMBO, ELISA M.
Lugar:
Benasque
Reunión:
Simposio; Engineering of the Eye III; 2011
Institución organizadora:
P. Artal (U. Murcia), D. R. Williams (U. Rochester, USA), C. Dainty (U. National, Ireland)
Resumen:
We have previously described a model that accounts for the influence of refractive correction on the parameters that determine the veiling luminance produced by a glare source: illuminance and angle. In this work we study the effect of a glare source on contrast sensitivity in mesopic lighting conditions when a subject wears glasses, adding to the study the effect of blur caused by incomplete refractive compensation. We measured contrast sensitivity (CS) for sinusoidal gratings with spatial frequencies of 2 and 16 c/d, an adaptation luminance of 0.5 cd/m2 in two emmetropics. To induce in these subjects different degrees of ammetropia, we used positive contact lenses (+2D and +5D) for myopia and negative contact lenses (-2D and -5D) for hyperopia. In all case induced ammetropia was corrected with ophthalmic lenses for the best visual acuity. Results are expressed as loss of sensitivity by mean of the relationship between CS with glare and CS without glare. The highest ratios were obtained for the condition of emmetropia, reduced in cases of induced ammetropia for both myopia and hyperopia. The model tested is only true qualitatively for the case of myopia, indicating that there are other factors to be considered. The measurements with ±0.25D additions produced a much greater loss of sensitivity than those can be explained by the effect of changes in the veiling luminance. These results warn about the importance of adequate compensation of ammetropia to prevent the effects of glare