Traditional diffractive multifocal lens implants are sometimes associated with unacceptably high levels of optical aberrations, haloes in the vision, and glare. Some authorities would actually not recommend diffractive multifocal implants in individuals needing to drive at night regularly, because of the potential for glare from oncoming headlights.
Accordingly the lens technology companies developed Extended Depth of Focus (EDOF) lenses which aimed to provide a smoother gradation between focal points in the vision with fewer aberrations. However in this randomised study of two competing EDOF lens types, there were still significant proportions of patients reporting starbursts, haloes, and glare in their vision.
In optics, there is no ‘free lunch,’ and every optical benefit comes with a compromise. These should be discussed in full with any patient considering multifocal, EDOF or other premium lens technologies.