The effect of ocular aberrations on steady-state errors of accommodative response

Abstract

It is well accepted that the accommodation system is characterized by steady-state errors in focus. The purpose of this study was to correlate these errors with changes in ocular wavefront aberration and corresponding image quality when accommodating. A wavefront analyzing system, the Complete Ophthalmic Analysis System (COAS), was used in conjunction with a Badal optometer to allow continuous recording of the aberration structure of the eye for a range of accommodative demands (up to 8 D). Fifty consecutive recordings from seven subjects were taken. Monocular accommodative response was calculated as (i) the equivalent refraction minimizing wavefront error and (ii) the defocus needed to optimize the modulation transfer function at high spatial frequencies. Previously reported changes in ocular aberrations with accommodation (e.g., the shift of spherical aberration to negative values) were confirmed. Increased accommodation errors for near targets (lags) were evident for all subjects, although their magnitude showed a significant intersubject variability. It is concluded that the one-to-one stimulus/response slope in accommodation function should not always be considered as ideal, because higher order aberrations, especially changes of spherical aberration, may influence the actual accommodative demand. Fluctuations may serve to preserve image quality when errors of accommodation are moderate, by temporarily searching for the best focus.

Static and dynamic crystalline lens accommodation evaluated using quantitative 3-D OCT

“…As OCT allows imaging the different optical surfaces of the eye, this study has extended previous reports on microfluctuations using ultrasonography that could only measure axial distances [49]. Some studies report a systematic increase of these fluctuations for increased accommodation [7,50], and other studies report a maximum value for intermediate levels of accommodation [5,11]. Our study has extended this work by assessing the isolated contributions of lens shape changes, and biometrical changes to the dynamics of accommodation.…”

“…the optical aberrations of the lens being typically computed as the difference of corneal and ocular wave aberrations). Also, the accommodative response of the lens is typically measured by monitoring refractive changes of the eye, using techniques such as dynamic retinoscopy [1], open-field autorefractometry [2], and aberrometry [3][4][5][6][7].…”

The influence of eye movements on monochromatic wavefront aberrations

“…Akkommodation an (He et al 2000, Krueger et al 2001, Plainis et al 2005. Ein gleichwohl variables Verhalten der Aberrationen höherer Ordnung fanden Pallikaris et al (2001).…”

“…Die sphärische Aberration zeigt im akkommodierten Auge einen eindeutigen Trend zu negativen Werten (He et al 2000, Artal et al 2002a, Ninomiya et al 2002, Cheng et al 2004a, Plainis et al 2005 Die Zernike-Koeffizienten höherer Ordnung bleiben bei Akkommodation annähernd gleich (Ninomiya et al 2002, He et al 2003, Cheng et al 2004a Dorronsoro et al 2003, Joslin et al 2003, Dietze und Cox 2004.…”

Disorders in melanopsin effect of pupil constriction as a risk factor causing eye diseases

“…Figure 9. Dependence of changes in pupil diameter on accommodation level S.Plainis in his work used the letter "E" printed on white paper lit by an incandescent lamp as an observation object [40]. Background brightness was equal to 5 cd/m2.…”