This is an alternative to laser eye surgery. It is ideal for people over 50 with short and long-sightedness who want to reduce their dependence on glasses or contact lenses. It is suitable even if you’ve got astigmatism or cataracts.
Trifocal lenses by Zeiss (AT LISA try 839MP) are an excellent option for patients who want a more complete range of focus after cataract or lens replacement surgery. To understand how these lenses work it is important to understand how the change of focus from close-up to distance and back again occurs in a youthful eye.
The cornea is the main lens of the eye accounting for two-thirds of the focussing of the eye; the crystalline lens accounts for the remainder. In a youthful state the crystalline lens has the ability to become gradually a wider and therefore more powerful lens allowing a seamless transition of focus from distance to near. The mechanisms by which this occurs are quite complex and not fully understood. As the eye ages the lens inside the eye, the crystalline lens, becomes less elastic and the transition of focus becomes less pronounced. This process, termed presbyopia, causes normal and long sighted people to require glasses for reading.
It is really important to understand that this fanstastic natural design cannot be perfectly replicated even with the most advanced lenses! However, the trifocal lens, comes close. The lens works by splitting the light entering the eye into separate points of focus. Most of the light, approximately 60%, is focussed for the distance with the remainder for close (at 40cm) and intermediate (80cm) vision.
I have been using these lenses for approximately five years and they still remain the best lens, in my opinion, for correcting presbyopia and distance vision simultaneously. The eye has to be in good health (i.e. other than cataract or refractive error) to be a candidate for this lens and equally importantly as a patient you need to aware of the benefits as well as the potential issues with cataract/lens surgery. Haloes around lights, especially at night, in the first few weeks are normal and settle as the brain adapts to a new way of seeing. In very low light, poor contrast situations and extremely small print may require a light or visual assistance.
It is important to distinguish between recognising halos and being disturbed by halos. It is true that patients are likely to recognise the presence of halos after trifocal lens implantation but the vast majority of patients are not disturbed by them. The Zeiss trifocal lens is designed specifically to minimise these effects.
As a surgeon I can only give you one point of view. The most important perspective comes from the patients who have undergone surgery with these lenses. At the open evenings you can hear first hand the experiences of those who have had the surgery and ask questions openly and get honest answers. You can also read through or watch some of the testimonials on the website. At your consultation you will also be given the option of speaking to past patients on a one to one basis to ensure that you have as much information from all perspectives to make the right decision for you.
How long it takes before I can see after surgery?
It is expected that immediately after surgery you will notice a significant improvement in vision.This is just the beginning.
Do my eyes need time to adapt?
It is normal that patients with multifocal IOLsgo through an adaption phase, continuing toimprove in the weeks following the procedure.It could take several weeks to realize the full extent of visual correction.
Why is time needed for adaption, and what is the process?
Multifocal IOLs project multiple images on the retina, which your brain uses for viewing objects at different distances. The brain must learn to select the visual information it needs to form an image of near, distant or intermediate objects.This adjustment time will vary for each patient.
What about halos?
With all multifocal IOLs, it is normal after surgery to experience some common visual disturbances. These may be more evident under poor light conditions, such driving at night. Rings of light, commonly called ‘halos’, may appear around street lights or oncoming car headlights. As the brain adapts, these effects will diminish and become less bothersome. A positive attitude and the awareness that your vision will improve will help you adapt
When will my second eye be operated on?
If you have cataracts in both eyes, your doctor will typically schedule a second surgery in the near future. You will adjust better to your multifocal intraocular lenses when they are placed in both eyes.
Will I need glasses after surgery?
For most patients, the desire for a life without glasses becomes a reality. However, even with an optimal surgical outcome, it may be necessary to use glasses for some activities such as reading or computer work, some of the time. This is a possible trade-off for the increased independence from glasses you can expect; and for many patients, the possibility of freedom from glasses that will last a lifetime.