Defocus correction in the optical system of the eye: unconventional degrees of freedom

摘要

Abstract. Despite the interest in developing improved formulas for intraocular lens power calculation, there arenseveral sources of uncertainty that may well give rise to a significant residual refractive error. Those concerningnthe estimation of the corneal power are reviewed. In addition, we explore the possibility of introducing changesnin some unconventional parameters of the eye to compensate for defocus and illustrate their effectiveness inntwo cases: a natural eye and an eye that has undergone previous surgical actions (anterior refractive surgerynand cataract surgery with an intraocular lens implant). The results show that changes in the refractive index,nthickness, or posterior radius of the cornea have relatively little effect on the overall refractive error. However,nsmall changes in the refractive indexes of the aqueous or the vitreous humors are highly effective, much morenso than a similar amount of change in the anterior curvature of the cornea. This fact opens new and attractivenpossibilities to compensate for refractive error through the introduction of changes in degrees of freedom so farnconsidered unconventional. C u00022011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3528619]