In a normal eye, the lens—which lies behind the pupil—is
clear (transparent), so the pupil appears black. In an eye with a severe
cataract, the cataract clouds the lens. So the pupil may look gray or
Close-up of a cataract
slide 2 of 8
slide 2 of 8, Close-up of a cataract,
The cornea is the clear layer that covers the front of the
eye. The lens is contained inside the eye's lens capsule. A cataract is a
partial or complete cloudiness in the lens.
Incision for surgical instrument is made
slide 3 of 8
slide 3 of 8, Incision for surgical instrument is made,
Two small cuts (incisions) are made in the eye where the
clear front covering of the eye (cornea) meets the white of the eye (sclera).
Next, a small, circular opening is made in the front of the lens capsule to allow access to the cataract. A small surgical instrument
(phaco probe) is inserted into the eye.
Lens is broken up and removed
slide 4 of 8
slide 4 of 8, Lens is broken up and removed,
The probe uses sound waves (ultrasound) to break the cataract into
small pieces. Then the surgeon uses suction to remove the cataract and lens pieces from the
eye. The surgeon may use a laser during parts of the surgery.
Intraocular lens (IOL)
slide 5 of 8
slide 5 of 8, Intraocular lens (IOL),
A variety of IOL types are available to replace your natural
lens. Your doctor can help you choose the type that may work best for
A lens replacement (IOL) is inserted
slide 6 of 8
slide 6 of 8, A lens replacement (IOL) is inserted,
After the cataract is removed, an intraocular lens (IOL) may
be placed inside the lens capsule. The
back of the lens capsule (posterior capsule) is left inside the eye to keep the clear gel in the
back of the eye (vitreous gel), as well as the IOL, in
Intraocular lens in place
slide 7 of 8
slide 7 of 8, Intraocular lens in place,
The intraocular lens (IOL) takes the place of the eye's
natural lens. The incision does not usually require stitches, unless the
surgeon decides they are needed.
Before and after cataract surgery
slide 8 of 8
slide 8 of 8, Before and after cataract surgery,
Before cataract surgery, the cloudy lens can be seen through
the pupil. After cataract surgery, the pupil appears black because the
intraocular lens is clear.
ByHealthwise Staff Primary Medical ReviewerKathleen Romito, MD - Family Medicine Specialist Medical ReviewerCarol L. Karp, MD - Ophthalmology
Kathleen Romito, MD - Family Medicine & Carol L. Karp, MD - Ophthalmology
The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.