The potential for and challenges of spherical and chromatic aberration correction with new IOL designs

摘要

When describing the human eye, celebrated scientist Hermann von Helmholtz once wrote 'Now it is not too much to say that if an optician wanted to sell me an instrument which had all these defects, I should think myself quite justified in blaming his carelessness in the strongest terms, and giving him back his instrument'. Helmholtz's assertion about the optics of the eye was quantified about a century later by Smirnov in Russia and the Howland brothers in the US, who found that normal human eyes exhibit significant levels of high-order aberrations, which can be much higher in eyes with corneal pathology, for instance, keratoconus. Laboratory studies and modern clinical aberrometers have allowed a large number of eyes to be measured in the last decade showing that aberrations of the unaccommodated eye are dominated by low-order (spherocylindrical refractive errors), third-order (coma and trefoil) and fourth-order spherical aberration (SA), as well as chromatic aberrations