If you’re looking into lens replacement surgery as a way of gaining independence from your glasses, you’ve probably heard of multifocal intraocular lenses (IOLs). But are they all they’re cracked up to be? This post looks at the various forms of intraocular lens available to you.
Who has this procedure?
Lens replacement surgery (also called clear lensectomy) is a popular alternative to LASIK for people who are over 50 and who wish to reduce their dependence on glasses.
It is a similar procedure to cataract surgery, apart from the fact that your lens is clear (not cloudy, as it is when you have a cataract). The contents of your natural crystalline lens are removed and replaced with an artificial lens, called an intraocular lens (or IOL). This means you can’t ever get a cataract in the future.
This vision correction procedure is popular with those who have had enough of being dependent on reading glasses or multifocals, particularly if their distance vision has also started to deteriorate during middle age. It doesn’t guarantee to rid you of your glasses completely, but usually means you are far less dependent on them for day-to-day tasks such as outdoor activities, meetings, seeing your phone, reading menus and price tags, etc. The various options are discussed below:
1. The Monofocal IOL
These are intraocular lenses which allow clear focus at one particular distance. Over 90% of patients having lens replacement surgery (or cataract surgery) in Australia today get this kind of IOL. These IOLs are very sophisticated in design and provide a very clear focus.
i) Distance Only
If there is any concern with your ocular health, such as early signs of macular degeneration, this is the best option. Both eyes are focused for distance to provide the best possible distance vision.
ii) Monovision (or blended vision)
If the goal is to maximise independence from reading glasses, many people have their dominant eye clearly focused for distance and the other eye focused for intermediate vision. (This may sound a little odd, but the two eyes are rarely the same, even in people who don’t wear glasses for distance). During your initial consultation prior to surgery, your surgeon will investigate if this will suit you.
2. The Trifocal or Multifocal IOL
These IOLs have been around in their current form for nearly a decade now and are becoming increasingly popular with people who seek the maximum independence from their glasses. They provide a focus at distance, intermediate and near in each eye. Sounds too good to be true? The fact is, it’s pretty good if you’re the right candidate (and if you’re not, can make you very unhappy). Good candidates for trifocal IOLs have healthy eyes, no dry eye disease and are comfortable with a compromise. And that compromise is in the quality and crispness of the vision, particularly in low-light conditions, such as driving at night. Everyone who gets a trifocal IOL will get some haloes or rings around lights at night. It becomes less noticeable over time (for up to a year after surgery) but it never fully goes away. For some people, whose goal is to be able to see as much as possible without glasses, this is a sacrifice they are willing to make. Other people who value the precision of their vision above complete spectacle independence are better off steering clear of these lenses. This is an important discussion your surgeon will have with you during your initial consultation.
3. The Toric IOL
These correct astigmatism, allowing a better result in terms of spectacle independence. Designs of toric lenses have improved dramatically over the past decade. The other thing that has improved is the technology used to place them inside your eye in precisely the right location to correct your vision. They are also available in multifocal and trifocal IOLs.
4. The Blue-Blocker IOL
These are also available across the range, in monofocal, trifocal and toric IOLs. The blue-blocker is a filter that blocks visible blue light from the end of the visible spectrum from entering your eye. Research is emerging that blue light can potentially harm the delicate tissues of the macula. It is naturally blocked by the crystalline lens of your eye, and this protection increases with age due to the natural yellowing of the lens. Once it is removed during cataract surgery, this protection is removed, so a blue-blocking filter can allow the new IOL to resume this protective role.
The best IOL for your eyes will be recommended by your surgeon, based on your unique needs and their experience with having performed the procedure for many years.