Multifocal lens are a boom for baby boomers
Laser eye surgery is very good at treating short-sightedness, long sightedness and astigmatism. This allows many patietns, particularly those under the age of 40 years, to have perfect vision without glasses.
The dilemma is with that large group of people who have a type of long-sighted called presbyopia.
Presbyopia is the loss of the ability to see things close to the eye without glasses. People say their 'arms are no longer long enough' to be able to hold something they want to read. Many older patients who have had cataract surgery have this problem but it is most commonly an irritating symptom of people in their 40's and 50's.
A typical scenario is someone who has never had to wear glasses starting to find they need help to read. They get a pair of glasses from their optometrist or a pair of 10 dollar 'look-overs' from a shop. These do them for a few years but then their distance vision starts to deteriorate as well. People find they need to wear their older 'reading' glasses just to see in the distance and an even stronger pair of glasses for reading!
Monovision
Until recently, the only way to help this group of patients was to operate on the eyes and mismatch them. We could make their dominant ('shooting') eye see perfectly well in the distance, whereas the operation on the other (non-dominant) eye would make the eye see well at close range. This is called Monovision. That is, one eye for distance and one eye for near.
Now, this may seem a little strange but, in fact, monovision is quite common naturally and many patients only realise that their eyes are different when they compare one against the other. Many people don't like the thought of having different eyes. They reject the idea of monovision as soon as we show what it would be like.
It is for this group of people that the new multifocal intraocular lens (IOL) technology is most useful.
Multifocal Intraocular Lens
Not to be confused with multifocal glasses, multifocal IOLs allow patient to see in the distance as well as at close range with BOTH eyes. There is no asymmetry and the whole arrangement is much more natural. They don't have to look through the top part of their glasses to see in the distance and the bottom part of their glasses to see up close as they do with multifocal or bifocal glasses.
Everything is in the one point of gaze.
The implantation of multifocal IOLs, the most successful being the ReSTOR IOL, involves a minor operation on the eyes which is very similar to cataract surgery. Actually, it is technically easier than a cataract operation but involves a little more care in ensuring that the calculations for the IOL are right.
This takes some expertise.
All things considered, there is less risk in performing such an operation (known as clear lens extraction or refractive lens exchange) than a cataract operation yet cataract surgery is considered to be one of the most common and successful operations medicine can offer. There is even the potential for such IOLs to be implanted in those who have already had cataract surgery. This will mean that patients who have had cataracts removed, but are dependent on glasses, will also have the possibility of freedom from spectacles or contacts lenses.
The RESTOR gives the opportunity for people who hate having to put on a pair of reading glasses to see things up close without having to remember to have their glasses handy. Prices in shops, menus in restaurants, SMS messages on mobile phones become easily visible as they come through unexpectedly. Plucking brows and putting on makeup is no longer a challenge when people have ReSTORs in their eyes. Interestingly, it is being able to perform these tasks without glasses that makes ReSTOR patients happiest, much more so than just being able to read a novel in the comfort of their lounge chair.