Refractive lens surgery

In refractive lens exchange (RLE), the natural lens is removed and replaced with an artificial one. There are several types, and the ophthalmologist will advise you on which suits your eyes and your everyday life best.

Monofocal lens

The classic lens with a single focal point. It makes you independent of distance glasses, whether you were previously short- or long-sighted. A good result requires a precise calculation of the lens power, which is measured with laser among other methods. If you have astigmatism, you should choose a toric lens.

Toric lens

With astigmatism, the eye does not have the same focal point in all directions, usually because the cornea is more oval than round. Toric lenses correct this and have been used in Denmark for almost 20 years with good results.

Multifocal lens

With age, the eye’s lens loses its ability to change focus, and from about the age of 45 it becomes difficult to read without glasses. A multifocal lens splits the light between at least two focal points, so there is always one image for distance and one for near. The brain automatically picks the sharp one.

EDOF lens

EDOF (Extended Depth of Focus) has one power, but modern optics give greater depth of focus, so you see sharply at several distances. It causes fewer rings ("halos") around light sources than multifocal lenses and gives more natural vision. On the other hand, near vision is not quite as good.

EDOF can be combined with monovision, where one eye is set for distance and the other for near. This can give better reading vision than two EDOF lenses set for distance.

Risks and side effects

Refractive lens surgery is the same operation as cataract surgery and is a safe, well-proven procedure. But it is an operation on an eye that often already sees well with glasses or contact lenses. That is why it is important that you know the risks before you decide. We always go through them with you at the pre-operative examination.

Halos and glare

Many people notice rings or rays around light sources in the dark, e.g. car headlights and street lights. This is most pronounced with multifocal lenses and less with EDOF and monofocal lenses. For most people the symptoms fade during the first months as the brain adapts to the lens. In a few they never disappear completely, and in rare cases the lens can be exchanged.

Reduced contrast vision

Multifocal lenses in particular split the light between several distances. This can give slightly duller vision in poor light and a greater need for good light when reading.

Retinal detachment

When the eye’s own lens is removed, the risk of retinal detachment increases slightly, even several years after the operation. The risk is highest in very short-sighted people, younger patients and men. Retinal detachment requires prompt surgery at a hospital eye department, so it is important to know the symptoms (see below).

Residual refractive error

Even with precise measurements, a small glasses prescription may remain. It can be corrected with glasses, laser treatment or, in rare cases, by exchanging the lens. A toric lens can rotate slightly in the eye and then needs to be adjusted.

Posterior capsule opacification

In about 20%, the capsule behind the lens becomes cloudy months to years after the operation. This is treated quickly and painlessly with laser. Read about posterior capsule opacification

Other possible complications

• Dry and irritated eyes at first
• Swelling of the macula (macular oedema), which causes blurred vision and is treated with eye drops
• Raised pressure in the eye in the days after the operation
• Infection inside the eye. This is very rare but serious and requires urgent treatment

You also lose the eye’s natural ability to change focus. If you are younger and can read without glasses today, this is an important part of the decision.