Cataract

What is a cataract?

A cataract is a clouding of the normally clear lens of the eye.  It can be compared to a window that is frosted or "fogged" with steam.

There are many misconceptions about cataract.  It is:

• Not a film over the eye;
• Not caused by overusing the eyes;
• Not a cancer;
• Not spread from one eye to the other;
• Not a cause of irreversible blindness.

Common symptoms of cataract include:

• A painless blurring of vision;
• Glare, or light sensitivity;
• Frequent eyeglass prescription changes;
• Double vision in one eye;
• Needing brighter light to read;
• Poor night vision;
• Fading or yellowing of colors.

The amount and pattern of cloudiness within the lens can vary.  If the cloudiness is not near the center of the lens, you may not be aware that a cataract is present.

What causes cataract?

The most common type of cataract is related to aging of the eye.  Other causes of cataract include:

• Family history;
• Medical problems, such as diabetes;
• Injury to the eye;
• Medications, such as steroids;
• Long-term, unprotected exposure to sunlight;
• Previous eye surgery.

How is a cataract detected?

A thorough eye examination by your ophthalmologist can detect the presence and extent of a cataract, as well as any other conditions that may be causing blurred vision or discomfort.

There may be other reasons for visual loss in addition to the cataract, particularly problems involving the retina or optic nerve.  If these problems are present, perfect vision may not return after cataract removal.

If such conditions are severe, removal of the cataract may not result in any improvement in vision.  Your ophthalmologist can tell you how much visual improvement is likely.

How fast does a cataract develop?

How quickly the cataract develops varies among individuals, and may vary even between the two eyes.  Most cataracts associated with aging progress gradually over a period of years.

Other cataracts, especially in younger people and people with diabetes, may progress rapidly over a few months and cause vision to worsen.  It is not possible to predict exactly how fast cataracts will develop in any given person.

How is cataract treated?

Surgery is the only way your ophthalmologist can remove the cataract.  However, if symptoms from a cataract are mild, a change of glasses may be all that is needed for you to function more comfortably.

There are no medications, dietary supplements, exercises or optical devices that have been shown to prevent or cure cataracts.

Protection from excessive sunlight may help prevent or slow the progression of cataracts.  Sunglasses that screen out ultraviolet (UV) light rays or regular eyeglasses with a clear, anti-UV coating offer this protection.

When should surgery be done?

Cataract surgery should be considered when cataracts cause enough loss of fision to interfere with daily activities.

It is not true that cataracts need to be "ripe" before they can be removed.

Cataract surgery can be performed when your visual needs require it.  You must decide if you can see to do your job and drive safely, if you can read and watch TV in comfort.  Can you perform daily tasks, such as cooking, shopping, yard work or taking medications without difficulty?

Based on your symptoms, you and your ophthalmologist should decide together when surgery is appropriate.

What can I expect from cataract surgery?

Over 1.4 million people have cataract surgery each year in the United States, 95% without complications.

During cataract surgery, which is usually performed under local anesthesia as an outpatient procedure, the cloudy lens is removed from the eye.  In most cases, the focusing power of the natural lens is restored by replacing it with a permanent intraocular lens implant.

Your ophthalmologist performs this delicate surgery using a microscope, miniature instruments and other modern technology.

Although it is a common misconception, lasers are not used to remove cataracts.

In approximately one-fifth of people having cataract surgery, the natural capsule that supports the intraocular lens will become cloudy.  Laser surgery is used to open this cloudy capsule, restoring the clear vision.

After cataract surgery, you may return almost immediately to all but the most strenuous activities.  You will have to take eye drops as your ophthalmologist directs.  Several postoperative visits are needed to check on the progress of the eye as it heals.

Cataract surgery is a highly successful procedure.  Improved vision is the result in over 90% of cases, unless there is a problem with the cornea, retina or optic nerve.  It is important to understand that complications can occur during or after the surgery, some severe enough to limit vision.  As with any surgery, a good result cannot be guaranteed.

Conclusion

Cataracts are a common cause of poor vision, particularly for the elderly, but they are treatable.  Your ophthalmologist can tell you whether cataract or some other problem is the cause for vision loss or discomfort, and help you decide if cataract surgery is appropriate for you.