There will definitely be a difference in visual outcome between patients who have multifocal lens implants versus monofocal ones. This is to be expected because the different lenses focus light a bit differently.
A monofocal lens will focus most light passing through it to a single focal distance, while a multifocal lens 'splits' the light passing through it to 2 or 3 focal distances.
This means that without glasses, a person with a monofocal lens sees clearest at one distance (either far or near, but not both), while without glasses, a person with a multifocal lens can see at both far and near.
Of course, a person with a monofocal lens can still see at other distances, as long as they use glasses-eg reading glasses for near if their monofocal gives them good distance vision.
Another way a person can use a monofocal lens to see at different distances is to use monofocal lenses to achieve 'monovision' ie to make one eye see well in the distance and make the other see well for near without glasses.
Even though a multifocal lens sounds better in theory, not everyone likes or may like a multifocal lens because there will be halos/rings around lights at night, and a somewhat reduced contrast compared to monofocal lenses. Therefore, multifocal lenses are not recommended for people who drive a lot at night, or who have other eye diseases affecting vision such as glaucoma or macular degeneration. Even people with normal eyes should consider the side effects of night time halos before deciding on whether to choose multifocal lenses or not.
Besides the above optical/visual differences, there are no other differences in outcomes eg of the risk of infection, floaters, etc.
