6533b857fe1ef96bd12b3b24

RESEARCH PRODUCT

Effect of 3rd-order aberrations on human vision

subject

description

To investigate the effect of 3rd-order aberrations on human vision.Grupo de Ciencias de la Visión, University of Murcia, Murcia, Spain.The 3rd-order aberrations coma and trefoil were induced with purpose-designed soft contact lenses, 3 inducing coma (low [0.05 microm], medium [0.13 microm], high [1.03 microm]) and 3 inducing trefoil (low [0.07 microm], medium [0.17 microm], high [0.96 microm]). Monocular high-contrast (HCVA) and low-contrast (LCVA) visual acuities and contrast sensitivity were measured in 11 subjects wearing contact lenses with a 5.0 mm artificial pupil.The reduction in HCVA and LCVA was statistically significant only for the highest coma and trefoil values (P.0001). For coma, the mean change in HCVA was 0.193 logMAR +/- 0.100 (SD) and in LCVA, 0.386 +/- 0.136 logMAR. For trefoil, it was 0.204 +/- 0.128 logMAR and 0.395 +/- 0.141 logMAR, respectively. No differences were found for the lower degrees (P.2). Contrast sensitivity was significantly reduced with the highest coma and trefoil values (P.0001) (mean change 0.390 +/- 0.157 and 0.404 +/- 0.135, respectively). Lower degrees did not cause significant changes in contrast sensitivity (P.1). The effect of induced coma and trefoil on HCVA, LCVA, and contrast sensitivity was similar at each level of induced aberration (P.01).Large values of coma and trefoil (approximately 1 mum) significantly reduced visual performance. Only patients with high 3rd-order aberrations, such as those that occur in refractive surgery or in cases of distorted optics, would benefit from this correction.