Optical imaging properties of multifocal IOL

ummary An increasing demand of spectacle independence after cataract surgery or clear lens extraction has greatly stimulated the development of multifocal intraocular lenses (MIOLs). Optical design has played an essential role in this progress. Based on the principle of simultaneous vision, MIOLs overcome the loss of accommodation by providing at least two primary powers intended for distance and near vision. Diffraction-based MIOLs have proved better optical performance than multizonal refractive MIOLs and accommodative IOLs. Some new designs of diffractive MIOLs attempt to direct light either to an intermediate focus location or to an extended focal segment for an improved visual acuity at intermediate distances. Although the patient primarily perceives the focused image, they can also experience disturbing visual phenomena, such as halos and glare. The optical imaging performance of MIOLs, as referred to some quality metrics, is assessed using in-vitro as well as in-vivo testing methods. This work reviews the objective imaging quality of a variety of MIOLs measured in an optical bench and compares the experimental results with those obtained in the clinical practice.