During cataract surgery, your eye's natural lens is removed and replaced with an intra-ocular lens (IOL). I will arrange for special investigations to work out what lens power to use. A standard monofocal lens will aim to give you great distance vision but it will mean that everything close up is blurry. You will require reading glasses for near vision such as reading and also for your intermediate vision, for example reading your tablet or computer. A multi-focal lens is designed to give you good near, intermediate and distance vision.
The technology is not perfect and it will not give you perfect distance and near vision but it should be pretty close. The vast majority of patients I have implanted with these lenses have found themselves independent of spectacles.
These lenses take the light energy and split it off into different focusing points. The brain gets two or three in focus images on the retina and it has to learn which one to notice and which to “see”. Once your brain adapts to the new way of seeing it will recognise what image it needs to use and ignore the other image(s).
Multifocal lenses deliver amazing results but they do have some compromises. They are not for everyone. We will need to decide together whether they are suitable for you once we assess your lifestyle, visual needs, clinical status and motivation for spectacle independence.
The AT Lisa (Zeiss) has multiple concentric rings to focus the light in different places. It looks a bit like the glass lens you see on a lighthouse light. The presence of those concentric rings cannot be completely problem free and glare is almost inevitable but thankfully tolerable in the vast majority of patients. Also because the energy of the light is split/reduced for each focal distance it means that if you have any problem with the macula (such as age related macular degeneration/wear and tear) this is not the lens for you.
This is a new lens from Zeiss which is described as an extended depth of focus lens (EDOF). Rather than splitting the light energy off into three distinct zones it blends the light energy over a greater depth of field. This gives you good distance and intermediate vision but near vision tends to be more of a struggle. This type of lens is ideal for those who want the benefit of a premium lens without the risk of visual side effects such as halos.
The Oculentis MPlus is a different lens which acts like a bifocal in the eye. It directs the light energy to two different focusing points but because there are no concentric rings glare does not appear to be a major problem. Also less light energy is lost so there is less worry about future macular problems.
The brain also adapts to these lenses easier.
If you want perfection then these will not give it to you but they will give you good quality vision. If you want a compromise and get good near and distance vision with the potential of a few visual side effects which are usually not particularly troublesome then these lenses could be an option for you.
Particularly with multifocal IOLs, you must be prepared for the possibility of at least some visual distortions — particularly in the form of glare and halos around light sources at night. These distortions rarely stop you night driving but in some people they can be annoying. If night driving is vital for you (for example if you are a lorry or taxi driver) then I would not recommend a multifocal lens.
Other reasons you may be eliminated as a candidate for multifocal IOLs include: