Spherical aberration and other higher-order aberrations in the human eye: from summary wave-front analysis data to optical variables relevant to visual perception.
Wave-front analysis data from the human eye are commonly presented using the aberration coefficient c(4)(0) (primary spherical aberration) together with an overall measure of all higher-order aberrations. If groups of subjects are compared, however, the relevance of an observed difference cannot easily be assessed from these summary aberration measures. A method was developed for estimating various optical variables relevant to visual perception from summary wave-front analysis data. These variables were the myopic shift (the difference in the optimal focus between high and low spatial frequencies, a threat to the simultaneous in-focus viewing of fine and coarse patterns), the depth-of-focus (at 8 cpd), and the modulation transfer at high (16 cpd; reading small print) and low (4 cpd; edge detection) spatial frequencies. The depth-of-focus was defined in two ways: using a relative measure (the full width at half-height of the through-focus curve) and an absolute measure (the range where the through-focus curve exceeds a predefined modulation transfer value). The method was shown to be accurate by using previously published contrast sensitivity data and wave-front analysis data. The applicability of the method was illustrated by applying the method to wave-front analysis measurements performed in pseudophakic patients with aspheric and spherical intraocular lenses.
Jansonius
Nomdo M
NM
Department of Ophthalmology, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands. n.m.jansonius@ohk.umcg.nl
D000328:Adult; D000368:Aged; D000375:Aging; D005123:Eye / Q000503:physiopathology*; D005128:Eye Diseases / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology; D055620:Optical Phenomena; D014796:Visual Perception