A cataract is a clouding of the normally clear lens of the eye. It can be compared to a window that is frosted or yellowed.
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.
There are many misconceptions about cataract. Cataract is not:
a film over the eye;
caused by overusing the eyes;
spread from one eye to the other;
a cause of irreversible blindness.
Common symptoms of cataract include:
a painless blurring of vision
glare, or light sensitivity
poor night vision
double vision in one eye
needing brighter light to read
fading or yellowing of colors
Left, normal vision. At right, dulled or yellowed vision.
Blurring or dimming of vision
What Causes Cataract?
The most common type of cataract is related to aging of the eye. Causes of cataract include:
medical problems, such as diabetes
injury to the eye
medications, especially steroids
long-term, unprotected exposure to sunlight
previous eye surgery
How Fast Does a Cataract Develop?
How quickly the cataract develops varies among individuals and may even be different between the two eyes. Most age-related cataracts progress gradually over a period of years.
In a normal eye, light focuses precisely on the retina.
In an eye with a cataract, light scatters throughout the eye instead of focusing precisely on the retina. Other cataracts, especially in younger people and people with diabetes, may progress rapidly over a short time. 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 a cataract can be removed. However, if symptoms of cataract are not bothering you very much, surgery may not be needed. Sometimes a simple change in your eyeglass prescription may be helpful.
No medications, dietary supplements or exercises have been shown to prevent or cure cataracts.
Protection from excessive sunlight may help 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.
How Is a Cataract Detected?
By performing a thorough eye examination, your ophthalmologist (Eye M.D.) can detect the presence of a cataract.
A careful evaluation will rule out any other conditions that may be causing blurred vision or other eye problems. Problems with other parts of the eye (such as the cornea, retina or optic nerve) can be responsible for vision loss and may prevent you from having much or any improvement in vision after cataract surgery. If improvement in your vision is unlikely, cataract removal may not be recommended. Your ophthalmologist can tell you how much visual improvement is likely.
When Should Surgery Be Done?
Surgery should be considered when cataracts cause enough loss of vision to interfere with your daily activities. It is not true that cataracts need to be "ripe" before they can be removed or that they need to be removed just because they are present.
Cataract surgery can be performed when your visual needs require it. You must decide if you can see well enough to do your job, drive safely, and read or watch TV in comfort. Does your vision allow you to perform daily tasks, such as cooking, shopping, doing 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 1.8 million people have cataract surgery each year in the United States, and more than 95 percent of those surgeries are performed with no complications.
During cataract surgery, which is usually performed under local or topical 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.
After surgery, you will have to take eyedrops as your ophthalmologist directs. Your surgeon will check your eye several times to make sure it is healing properly.
Cataract surgery is a highly successful procedure. Improved vision is the result in over 95 percent of cases, unless there is a problem with the cornea, retina, optic nerve or other structures. It is important to understand that complications can occur during or after the surgery, some severe enough to limit vision. If you experience even the slightest problem after cataract surgery, your ophthalmologist will want to hear from you immediately.
In many people who have cataract surgery, the natural capsule that supports the intraocular lens becomes cloudy. If this occurs, your ophthalmologist can perform an outpatient laser procedure to open this cloudy capsule, restoring clear vision.
Cataracts are a common cause of decreased vision, particularly for the elderly, but they are treatable. Your ophthalmologist can tell you whether cataract or some other problem is the cause of your vision loss and can help you decide if cataract surgery is appropriate for you.
What is a cataract?
A cataract is a clouding of the eye's naturally clear lens. The lens focuses light rays on the retina, the layer of light-sensing cells lining the back of the eye, to produce a sharp image of what we see. When the lens becomes cloudy, light rays cannot pass through it easily, and vision is blurred.
Light rays entering an eye with a cataract. When a cataract forms, the lens of your eye is cloudy. Light cannot pass through it easily, and your vision
What causes cataracts?
Cataract development is a normal process of aging, but cataracts also develop from eye injuries, certain diseases or medications. Your genes may also play a role in cataract development.
How can a cataract be treated?
A cataract may not need to be treated if your vision is only slightly blurry. Simply changing your eyeglass prescription may help to improve your vision for a while. There are no medications, eyedrops, exercises or glasses that will cause cataracts to disappear once they have formed. Surgery is the only way to remove a cataract. When you are no longer able to see well enough to do the things you like to do, cataract surgery should be considered.
In cataract surgery, the cloudy lens is removed from the eye through a surgical incision. In most cases, the natural lens is replaced with a permanent intraocular lens (IOL) implant.
What can I expect if I decide to have cataract surgery?
Before Surgery To determine if your cataract should be removed, your ophthalmologist (Eye M.D.) will perform a thorough eye examination. Before surgery, your eye will be measured to determine the proper power of the intraocular lens that will be placed in your eye. Ask your ophthalmologist if you should continue taking your usual medications before surgery.
You should make arrangements to have someone drive you home after surgery.
The Day of Surgery Surgery is usually done on an outpatient basis, either in a hospital, an outpatient surgical center, or an ambulatory surgery center. You may be asked to skip breakfast, depending on the time of your surgery.
When you arrive for surgery, you will be given eyedrops and perhaps a mild sedative to help you relax. A local anesthetic will numb your eye. The skin around your eye will be thoroughly cleansed, and sterile coverings will be placed around your head. Your eye will be kept open by an eyelid speculum. You may see light and movement, but you will not be able to see the surgery while it is happening.
Under an operating microscope, a small incision is made in the eye. In most cataract surgeries, tiny surgical instruments are used to break apart and remove the cloudy lens from the eye. The back membrane of the lens (called the posterior capsule) is left in place.
During cataract surgery, tiny instruments are used to break apart and remove the cloudy lens from the eye.
An intraocular lens (IOL) implant.
In cataract surgery, the intraocular lens replaces the eye's natural lens. After surgery is completed, your doctor may place a shield over your eye. After a short stay in the outpatient recovery area, you will be ready to go home.
Following Surgery You will need to:
Use the eyedrops as prescribed Be careful not to rub or press on your eye Avoid strenuous activities until your ophthalmologist tells you to resume them Ask your doctor when you can begin driving Wear eyeglasses or an eye shield, as advised by your doctor You can continue most normal daily activities. Over-the-counter pain medicine may be used, if necessary. Is a laser used during cataract surgery?
Laser surgery is not used in cataract removal surgery. However, the lens capsule (the part of the eye that holds the lens in place) sometimes becomes cloudy several months or years after the original cataract operation. If the cloudy capsule blurs your vision, your ophthalmologist can perform a second surgery using a laser. During the second procedure, called a posterior capsulotomy, a laser is used to make an opening in the cloudy lens capsule, restoring normal vision.
Posterior capsulotomy: a laser is used to make an opening in the cloudy lens capsule. Will cataract surgery improve my vision?
The success rate of cataract surgery is excellent. Improved vision is achieved in the majority of patients. Only a small number of patients continue to have problems following cataract surgery.
Complications After Cataract Surgery
Though they rarely occur, serious complications of cataract surgery are:
Infection Bleeding Swelling Detachment of the retina Call your ophthalmologist immediately if you have any of the following symptoms after surgery: Pain not relieved by nonprescription pain medication Loss of vision Nausea, vomiting, or excessive coughing Injury to the eye Even if cataract surgery is successful, some patients may not see as well as they would like to. Other eye problems such as macular degeneration (aging of the retina), glaucoma or diabetic retinopathy may limit vision after surgery. Even with these problems, cataract surgery may still be worthwhile.