Treatments · Premium Lens
In cataract surgery, or to reduce dependence on glasses, an intraocular lens (IOL) suited to the individual is placed in place of the natural lens. On this page you will find the lens types, how they focus light and what may suit whom.
Inside the eye, behind the pupil, there is a natural lens that focuses incoming light onto the retina. In cataract surgery this clouded lens is removed and a clear intraocular lens is placed into the natural pouch called the capsule. This lens is permanent and takes over part of the eye's focusing power.
The image below shows the actual appearance of the main lens types; the diagrams beneath show how each type focuses light.
It has a single focal point, usually set for distance. Distant rays converge sharply on the retina; reading glasses may be needed for near. It offers the highest contrast and the best night-vision quality.
Optically it is still single-focus, but a slight power increase in the center extends the focus somewhat, adding a little for intermediate distance (computer, car dashboard). The night-vision profile stays similar to a monofocal.
An astigmatic cornea is shaped like a rugby ball: steeper in one axis and flatter in the other, so it cannot bring light to a single point. A toric lens balances this with different power in the two axes. Axis alignment is critical: the lens must sit at the correct angle.
The concentric rings on its surface (diffractive steps) split incoming light into several foci at once: distance, intermediate and near. The brain selects the image that is in focus. Because the light is split, halos/glare around lights at night and a slight loss of contrast can occur.
Instead of separate foci, it stretches a single focus over a continuous range. It gives good distance and intermediate vision and partial near vision; night-vision effects are usually fewer/softer than with a trifocal.
General rule: as spectacle independence increases, night-vision effects (halos/glare) tend to increase too. The ideal choice is made along this balance according to your priority.
The steps below schematically show the typical flow of cataract / premium lens surgery. Use the forward/back arrows to move through them.
Vision usually clears gradually over a few days to weeks; the prescribed drops are used regularly, and rubbing the eye and heavy straining are avoided for a while. With multifocal/EDOF lenses, the brain's adaptation to the new image (neuroadaptation) can take weeks to months.
Months to years later, the membrane behind the lens (the posterior capsule) can become cloudy; this is called posterior capsule opacification (PCO) and is not the cataract "coming back." It is resolved with a short, painless YAG laser procedure.
1. Your age range?
2. What is your vision priority?
3. How often do you drive at night?
4. How much near work do you do (reading, phone, handcraft)?
5. Have you been told you have astigmatism?
6. How important is full independence from glasses to you?
7. Your tolerance for effects like halos/glare around lights at night?
8. Do you have any known eye condition?
ESTIMATED SUGGESTION, NOT A DIAGNOSIS
Remember: This is only a starting point. The real choice is made together with your doctor after your eye's measurements and examination.
The lens that is removed does not come back. Later cloudiness is usually posterior capsule opacification (PCO) and is treated with a YAG laser.
No. In conditions such as macular disease, advanced glaucoma, severe dry eye or an irregular cornea, a monofocal lens is often more suitable for the sharpest and safest vision.
In most people the need for glasses drops markedly, but it is not guaranteed; night halos/glare can occur and it is not suitable for every eye. Clarifying expectations beforehand is important.
Usually no. Modern surgery is often easier and safer with softer cataracts; the timing is set according to your visual needs.
FLACS adds precision at certain steps; however, in routine cases a clear superiority in the final visual outcome has not been proven. The method is assessed individually.
The final decision is made after biometry and a detailed examination. Contact me for an appointment.