Lens implants are used either to replace
the natural lens in cases of cataracts and other lens damage, or to replace or
supplement the natural lens to enhance vision in cases of long sight, short
sight or astigmatism. Lens implants are permanent and designed to last a
lifetime, although implantable collamer lenses (ICLs) can be removed and
replaced easily if your vision significantly changes.
Refractive lens exchange
In refractive lens exchange (RLE) lens
implants are used to replace the existing lens:
Monofocal lenses that have equal power
across the lens and provide good general distance vision.
Toric lenses that correct both
shortsightedness and astigmatism.
Multifocal lenses that allow for both good
distance and close up vision.
Trifocal lenses that give intermediate
vision as well as distance and close up.
Light adjustable lenses that are adjusted a
week after implantation using UV light to sculpture the final shape of the lens
in the eye.
People who have monofocal or toric lens
implants usually require reading glasses for close up work, since the
replacement lens is not able to adapt its focal length in the same way as a
natural lens. The most advanced lens implants usually give the recipient
complete freedom from glasses and contacts.
Phakic implantable collamer lenses do not
replace the existing natural eye lens, but sit in front of it like an internal
contact lens. Since the natural lens is retained, this type of implant provides
a far wider range of vision and the recipient does not normally require reading
Once implanted, phakic lenses cannot be seen
in the eye, as they cover the whole of the pupil opening and have their edges
tucked under the iris.
Who are lens implants suitable for?
Lens implants are a vital part of any
procedure where the existing lens has to be removed and replaced, such as cataract
surgery. However, lens transplants, especially ICL transplants, are becoming
more and more common for people who have short or long sight, but who are
unsuitable for corrective laser surgery. These include
People with a short sight prescription greater
People with a long sight prescription
greater than +6.0D.
People with thin corneas.
People at risk from complications of laser
ICL transplants can correct prescriptions
up to -25.0D in short sight and +12.0D in long sight, as well as astigmatism up
to 5.0D. These are all severe visual defects.
Phakic lens implants are normally only
recommended for people under 45, who have a good quality natural lens. In older
people, this lens has often started to degenerate, making full lens replacement
a more practical option.
Lens implant surgery
Lens implant surgery is usually done under
local anaesthetic on an out-patient basis. Both the removal of the existing
lens (if required) and implantation of the replacement or supplementary lens,
are done through a very small incision. The procedure takes less than half an
You will only be able to have one lens
implanted at a time. If you need lens implants in both eyes, you may need to
wear a single contact lens, or specially adapted glasses in between the two
treatments. The second implant is usually done around a week after the first.
It can take a day or two for your vision to
fully recover following full lens replacement. You can notice much faster
improvements after implantation of a phakic lens.
Risks and complications of lens implants
Phakic lens implants carry few risks, as
the surgery is limited to a small incision and the lens is made of a special
material to reduce the possibility of rejection by the body.
Full lens replacement carries additional
risks, as it’s a more extensive procedure. The most common complication is
posterior capsule opacification. This occurs when the back of the replacement
lens becomes thicker and clouds the vision and further surgery is then
Rare complications include rejection of the
lens by the body, retinal detachment, glaucoma or a reduction in vision,
especially at night.