Ophthalmology Services

Cataract surgery is a procedure to remove the lens of your eye and, in most cases, replace it with an artificial lens. Normally, the lens of your eye is clear. A cataract causes the lens to become cloudy, which eventually affects your vision.

Cataract surgery is performed by an eye doctor (ophthalmologist) on an outpatient basis, which means you don't have to stay in the hospital after the surgery. Cataract surgery can be done traditionally using ultrasound energy to remove the cloudy lens or it can be removed with laser-assisted technology. Cataract surgery is very common and is generally a safe procedure.

Why it's done

How a cataract affects your vision How a cataract affects your vision Cataract surgery is performed to treat cataracts. Cataracts can cause blurry vision and increase the glare from lights. If a cataract makes it difficult for you to carry out your normal activities, your doctor may suggest cataract surgery.

When a cataract interferes with the treatment of another eye problem, cataract surgery may be recommended. For example, doctors may recommend cataract surgery if a cataract makes it difficult for your eye doctor to examine the back of your eye to monitor or treat other eye problems such as age-related macular degeneration or diabetic retinopathy.

In most cases, waiting to have cataract surgery won't harm your eye, so you have time to consider your options. If your vision is still quite good, you may not need cataract surgery for many years, if ever.

When considering cataract surgery, keep these questions in mind:

• Can you see to safely do your job and to drive?
• Do you have problems reading or watching television?
• Is it difficult to cook, shop, do yardwork, climb stairs or take medications?
• Do vision problems affect your level of independence?
• Do bright lights make it more difficult to see?

Risks

Complications after cataract surgery are uncommon, and most can be treated successfully.

Cataract surgery risks include:

• Inflammation
• Infection
• Bleeding
• Swelling
• Drooping eyelid
• Dislocation of artificial lens
• Retinal detachment
• Glaucoma
• Secondary cataract
• Loss of vision

Your risk of complications is greater if you have another eye disease or a serious medical condition. Occasionally, cataract surgery fails to improve vision because of underlying eye damage from other conditions, such as glaucoma or macular degeneration. If possible, it may be beneficial to evaluate and treat other eye problems before making the decision to have cataract surgery.

How you prepare

To prepare for your cataract surgery, you may be asked to:

• Undergo tests. A week or so before your surgery, your doctor performs a painless ultrasound test to measure the size and shape of your eye. This helps determine the right type of lens implant (intraocular lens, or IOL).
• Stop taking certain medications. Your doctor may advise you to temporarily stop taking any medication that could increase your risk of bleeding during the procedure. Let your doctor know if you take any medications for prostate problems, as some of these drugs can interfere with cataract surgery.
• Use eyedrops to reduce infection risk. Antibiotic eyedrops may be prescribed for use one or two days before the surgery.
• Fast before surgery. You may be instructed not to eat or drink anything 12 hours before the procedure.
• Prepare for your recovery. Normally you can go home on the same day as your surgery, but you won't be able to drive, so arrange for a ride home. Also arrange for help around home, if necessary, because your doctor may limit activities, such as bending and lifting, for about a week after your surgery.

What you can expect

Before cataract surgery

Nearly everyone who has cataract surgery will be given an artificial lens called an intraocular lens (IOL). These lenses improve your vision by focusing light on the back of your eye.

You won't be able to see or feel the lens. It requires no care and becomes a permanent part of your eye.

A variety of IOLs with different features are available. Before surgery, you and your eye doctor will discuss which type of intraocular lens (IOL) might work best for you and your lifestyle. Cost may also be a factor, as insurance companies may not pay for all types of lenses.

IOLs are made of plastic, acrylic or silicone. Some IOLs block ultraviolet light. Some IOLs are rigid plastic and implanted through an incision that requires several stitches (sutures) to close.

However, many IOLs are flexible, allowing a smaller incision that requires few or no stitches. The surgeon folds this type of lens and inserts it into the empty capsule where the natural lens used to be. Once inside the eye, the folded IOL unfolds, filling the empty capsule.

Some of the types of lenses available include:

• Fixed-focus monofocal. This type of lens has a single focus strength for distance vision. Reading will generally require the use of reading glasses.
• Accommodating-focus monofocal. Although these lenses only have a single focusing strength, they can respond to eye muscle movements and shift focus on to near or distant objects.
• Multifocal. These lenses are similar to glasses with bifocal or progressive lenses. Different areas of the lens have different focusing strengths, allowing for near, medium and far vision.
• Astigmatism correction (toric). If you have a significant astigmatism, a toric lens can help correct your vision.

Discuss the benefits and risks of the different types of IOLs with your eye surgeon to determine what's best for you.

During cataract surgery

Cataract surgery, usually an outpatient procedure, takes an hour or less to perform.

First, your doctor will place eyedrops in your eye to dilate your pupil. You'll receive local anesthetics to numb the area, and you may be given a sedative to help you relax. If you're given a sedative, you may remain awake, but groggy, during surgery.

During cataract surgery, the clouded lens is removed, and a clear artificial lens is usually implanted. In some cases, however, a cataract may be removed without implanting an artificial lens.

Surgical methods used to remove cataracts include:

• Using an ultrasound probe to break up the lens for removal. During a procedure called phacoemulsification (fak-o-e-mul-sih-fih-KAY-shun), your surgeon makes a tiny incision in the front of your eye (cornea) and inserts a needle-thin probe into the lens substance where the cataract has formed.
  Your surgeon then uses the probe, which transmits ultrasound waves, to break up (emulsify) the cataract and suction out the fragments. The very back of your lens (the lens capsule) is left intact to serve as a place for the artificial lens to rest. Stitches may or may not be used to close the tiny incision in your cornea at the completion of the procedure.
• Using an advanced laser technique to remove the cloudy lens. In laser-assisted cataract surgery, the surgeon uses a laser to make all incisions and soften the cataract for removal.
• Making an incision in the eye and removing the lens in one piece. A less frequently used procedure called extracapsular cataract extraction requires a larger incision than that used for phacoemulsification. Through this larger incision your surgeon uses surgical tools to remove the front capsule of the lens and the cloudy portion of your lens comprising the cataract. The very back capsule of your lens is left in place to serve as a place for the artificial lens to rest.
  This procedure may be performed if you have certain eye complications. With the larger incision, stitches are required.

Once the cataract has been removed by either phacoemulsification or extracapsular extraction, the artificial lens is implanted into the empty lens capsule.

After cataract surgery

After cataract surgery, expect your vision to begin improving within a few days. Your vision may be blurry at first as your eye heals and adjusts.

Colors may seem brighter after your surgery because you are looking through a new, clear lens. A cataract is usually yellow- or brown-tinted before surgery, muting the look of colors.

You'll usually see your eye doctor a day or two after your surgery, the following week, and then again after about a month to monitor healing.

It's normal to feel itching and mild discomfort for a couple of days after surgery. Avoid rubbing or pushing on your eye.

Your doctor may ask you to wear an eye patch or protective shield the day of surgery. Your doctor may also recommend wearing the eye patch for a few days after your surgery and the protective shield when you sleep during the recovery period.

Your doctor may prescribe eyedrops or other medication to prevent infection, reduce inflammation and control eye pressure. Sometimes, steroid medications can be injected into the eye at the time of surgery to keep inflammation at bay.

After a couple of days, most of the discomfort should disappear. Often, complete healing occurs within eight weeks.

Contact your doctor immediately if you experience any of the following:

• Vision loss
• Pain that persists despite the use of over-the-counter pain medications
• Increased eye redness
• Light flashes or multiple new spots (floaters) in front of your eye

Most people need glasses, at least some of the time, after cataract surgery. Your doctor will let you know when your eyes have healed enough for you to get a final prescription for eyeglasses. This is usually between one and three months after surgery.

If you have cataracts in both eyes, your doctor usually schedules the second surgery after the first eye has healed.

Results

Cataract surgery successfully restores vision in the majority of people who have the procedure.

People who've had cataract surgery may develop a secondary cataract. The medical term for this common complication is known as posterior capsule opacification (PCO). This happens when the back of the lens capsule — the part of the lens that wasn't removed during surgery and that now supports the lens implant — becomes cloudy and impairs your vision.

PCO is treated with a painless, five-minute outpatient procedure called yttrium-aluminum-garnet (YAG) laser capsulotomy. In YAG laser capsulotomy, a laser beam is used to make a small opening in the clouded capsule to provide a clear path through which the light can pass.

After the procedure, you usually stay in the doctor's office for about an hour to make sure your eye pressure doesn't rise. Other complications are rare but can include increased eye pressure and retinal detachment.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.

An eye exam involves a series of tests to evaluate your vision and check for eye diseases. Your eye doctor may use a variety of instruments, shine bright lights directly at your eyes and request that you look through an array of lenses. Each test during an eye exam evaluates a different aspect of your vision or eye health.

Why it's done

An eye exam helps detect eye problems at their earliest stage — when they're most treatable. Regular eye exams give your eye care professional a chance to help you correct or adapt to vision changes and provide you with tips on caring for your eyes.

When to have an eye exam

Several factors may determine how frequently you need an eye exam, including your age, health and risk of developing eye problems. General guidelines are as follows:

Children 5 years and younger. For children under 3, your pediatrician will likely look for the most common eye problems — lazy eye, crossed eyes or turned-out eyes. Depending on your child's willingness to cooperate, he or she could undergo a more-comprehensive eye exam between the ages of 3 and 5.

School-age children and adolescents. Have your child's vision checked before he or she enters first grade. If your child has no symptoms of vision problems and no family history of vision problems, have his or her vision rechecked every one to two years. Otherwise, schedule eye exams based on the advice of your eye doctor.

Adults. In general, if you're healthy and have no symptoms of vision problems, have your eyes checked on this schedule:

• Every five to 10 years in your 20s and 30s
• Every two to four years from 40 to 54
• Every one to three years from 55 to 64
• Every one to two years after age 65

Have your eyes checked more often if you:

• Wear glasses or contact lenses
• Have a family history of eye disease
• Have a chronic disease that puts you at greater risk of eye disease, such as diabetes

How you prepare

Three kinds of eye specialists may perform an eye exam:

• Ophthalmologists. Ophthalmologists are medical doctors who provide full eye care, such as giving you a complete eye exam, prescribing corrective lenses, diagnosing and treating complex eye diseases, and performing eye surgery.
• Optometrists. Optometrists provide many of the same services as ophthalmologists, such as evaluating your vision, prescribing corrective lenses, diagnosing common eye disorders and treating selected eye diseases with drugs. If you have a complex eye problem or need surgery, your doctor can refer you to an ophthalmologist.
• Opticians. Opticians fill prescriptions for eyeglasses, including assembling, fitting and selling them. Some opticians also sell contact lenses.

Which specialist you choose may be a matter of personal preference or will depend on the nature of your eye problem.

What you can expect from your doctor

If you're seeing a new eye doctor or if you're having your first eye exam, expect questions about your vision history. Your answers help your eye doctor understand your risk of eye disease and vision problems. Be prepared to give specific information, including:

• Are you having any eye problems now?
• Have you had any eye problems in the past?
• Were you born prematurely?
• Do you wear glasses or contacts now? If so, are you satisfied with them?
• What health problems have you had in recent years?
• Are you taking any medications?
• Do you have any allergies to medications, food or other substances?
• Have you ever had eye surgery?
• Does anyone in your family have eye problems, such as macular degeneration or glaucoma?
• Do you or does anyone in your family have diabetes, high blood pressure, heart disease or any other health problems that can affect the whole body?

If you wear contact lenses or glasses, bring them to your appointment. Your eye doctor will want to make sure your prescription is the best one for you. Also be prepared to remove your contacts or glasses during the exam. Tests that use dye (fluorescein) to temporarily color your eyes may permanently discolor your contact lenses, so you'll be asked to remove them for those tests.

If your eyes are dilated as a part of your eye exam, you may want to bring sunglasses to wear after your eye exam is complete, as daylight or other bright lights may be uncomfortable or cause blurred vision. Also, consider having someone else drive you home.

What you can expect

An eye exam usually involves these steps:

• You'll be asked about your medical history and any vision problems you might be experiencing.
• Your eye doctor measures your visual acuity to see if you need glasses or contact lenses to improve your vision.
• You'll be given numbing drops in your eyes. Then your doctor measures your eye pressure.
• Your eye doctor checks the health of your eyes, possibly using several lights to evaluate the front of the eye and inside of each eye. To make it easier for your doctor to examine the inside of your eye, he or she will likely dilate your eyes with eyedrops.
• Your eye doctor discusses what he or she found during the exam and answers questions you have about your eyes.

Part of the examination, such as taking your medical history and the initial eye test, may be performed by a clinical assistant.

Several different tests may be performed during the eye exam. The tests are designed to check your vision and to examine the appearance and function of all parts of your eyes.

Eye muscle test

This test evaluates the muscles that control eye movement. Your eye doctor watches your eye movements as you follow a moving object, such as a pen or small light, with your eyes. He or she looks for muscle weakness, poor control or poor coordination.

Visual acuity test

This test measures how clearly you see. Your doctor asks you to identify different letters of the alphabet printed on a chart (Snellen chart) or a screen positioned some distance away. The lines of type get smaller as you move down the chart. Each eye is tested separately. Your near vision also may be tested, using a card with letters similar to the distant eye. The card is held at reading distance.

Refraction assessment

Light waves are bent as they pass through your cornea and lens. If light rays don't focus perfectly on the back of your eye, you have a "refractive error." Having a refractive error may mean you need some form of correction, such as glasses, contact lenses or refractive surgery, to see as clearly as possible. Assessment of your refractive error helps your doctor determine a lens prescription that will give you the sharpest, most comfortable vision. The assessment may also determine that you don't need corrective lenses.

Your doctor may use a computerized refractor to estimate your prescription for glasses or contact lenses. Or he or she may use a technique called retinoscopy. In this procedure, the doctor shines a light into your eye and measures the refractive error by evaluating the movement of the light reflected by your retina back through your pupil.

Your eye doctor usually fine-tunes this refraction assessment by having you look through a mask-like device that contains wheels of different lenses (phoropter). He or she asks you to judge which combination of lenses gives you the sharpest vision.

Visual field test (perimetry)

Your visual field is the full extent of what you can see to the sides without moving your eyes. The visual field test determines whether you have difficulty seeing in any areas of your overall field of vision. The different types of visual field tests include:

• Confrontation exam. Your eye doctor sits directly in front of you and asks you to cover one eye. You look straight ahead and tell the doctor each time you see his or her hand move into view.
• Tangent screen exam. You sit a short distance from a screen and focus on a target at its center. You tell the doctor when you can see an object move into your peripheral vision and when it disappears.
• Automated perimetry. As you look at a screen with blinking lights on it, you press a button each time you see a blink.

Using your responses to one or more of these tests, your eye doctor determines the fullness of your field of vision. If you aren't able to see in certain areas, noting the pattern of your visual field loss may help your eye doctor diagnose your eye condition.

Color vision testing

You could have poor color vision and not even realize it. If you have difficulty distinguishing certain colors, your eye doctor may screen your vision for a color deficiency. To do this, your doctor shows you several multicolored dot-pattern tests. If you have no color deficiency, you'll be able to pick out numbers and shapes from within the dot patterns. If you do have a color deficiency, you'll find it difficult to see certain patterns within the dots. Your doctor may use other tests, as well.

Slit-lamp examination

A slit lamp is a microscope that magnifies and illuminates the front of your eye with an intense line of light. Your doctor uses this device to examine the eyelids, lashes, cornea, iris, lens and fluid chamber between your cornea and iris.

Your doctor may use a dye, most commonly fluorescein (flooh-RES-een), to color the film of tears over your eye. This helps reveal any damaged cells on the front of your eye. Your tears wash the dye from the surface of your eye fairly quickly.

Retinal examination

A retinal examination — sometimes called ophthalmoscopy or funduscopy — allows your doctor to evaluate the back of your eye, including the retina, the optic disk and the underlying layer of blood vessels that nourish the retina (choroid). Usually before your doctor can see these structures, your pupils must be dilated with eyedrops that keep the pupil from getting smaller when your doctor shines light into the eye.

After administering eyedrops and giving them time to work, your eye doctor may use one or more of these techniques to view the back of your eye:

• Direct exam. Your eye doctor uses an ophthalmoscope to shine a beam of light through your pupil to see the back of the eye. Sometimes eyedrops aren't necessary to dilate your eyes before this exam.
• Indirect exam. During this exam, you might lie down, recline in a chair or sit up. Your eye doctor examines the inside of the eye with the aid of a condensing lens and a bright light mounted on his or her forehead. This exam lets your doctor see the retina and other structures inside your eye in great detail and in three dimensions.

Screening for glaucoma

Tonometry measures the fluid pressure inside your eye (intraocular pressure). This test helps your eye doctor detect glaucoma, a disease that damages the optic nerve.

Several methods to measure intraocular pressure are available, including:

• Applanation tonometry. This test measures the amount of force needed to temporarily flatten a part of your cornea. You'll be given eyedrops with fluorescein, the same dye used in a regular slit-lamp examination. You'll also receive eyedrops containing an anesthetic. Using the slit lamp, your doctor moves the tonometer to touch your cornea and determine the eye pressure. Because your eye is numbed, the test doesn't hurt.
• Noncontact tonometry. This method uses a puff of air to estimate the pressure in your eye. No instruments touch your eye, so you won't need an anesthetic. You'll feel a momentary pulse of air on your eye, which can be startling.

If your eye pressure is higher than average or your optic nerve looks unusual, your doctor may use a pachometer. This instrument uses sound waves to measure the thickness of your cornea. The most common way of measuring corneal thickness is to put an anesthetic drop in your eye, then place a small probe in contact with the front surface of the eye. The measurement takes seconds.

You may need more-specialized tests, depending on your age, medical history and risk of developing eye disease.

Results

At the end of your eye exam, you and your doctor will discuss the results of all testing, including an assessment of your vision, your risk of eye disease and preventive measures you can take to protect your eyesight.

Normal results from an eye exam include:

• 20/20 vision
• Good peripheral vision
• Ability to distinguish various colors
• Normal-appearing structures of the external eye
• Absence of cataract, glaucoma or retinal disorders, such as macular degeneration

Your doctor may give you a prescription for corrective lenses. If your eye exam yields other abnormal results, your doctor will discuss with you next steps for further testing or for treating an underlying condition.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.

If you get a foreign object in your eye

• Wash your hands with soap and water.
• Try to flush the object out of your eye with a gentle stream of clean, warm water. Use an eyecup or a small, clean drinking glass positioned with its rim resting on the bone at the base of your eye socket.
• Another way to flush a foreign object from your eye is to get into a shower and aim a gentle stream of lukewarm water on your forehead over the affected eye while holding your eyelid open.
• If you're wearing contact lenses, it's best to remove the lens before or while you're irrigating the surface of the eye with water. Sometimes a foreign body can be embedded on the undersurface of the lens.

To help someone else

• Wash your hands with soap and water.
• Seat the person in a well-lighted area.
• Gently examine the eye to find the object. Pull the lower lid down and ask the person to look up. Then hold the upper lid while the person looks down.
• If the object is floating in the tear film on the surface of the eye, try using a medicine dropper filled with clean, warm water to flush it out. Or tilt the head back and irrigate the surface of the eye with clean water from a drinking glass or a gentle stream of tap water.

Caution

• Don't try to remove an object that's embedded in the eye.
• Don't rub the eye.
• Don't try to remove a large object that appears to be embedded in the eye or is sticking out between the lids.

When to seek emergency care

Get immediate medical help if:

• You can't remove the object with simple irrigation
• The object is embedded in the eye
• The person with the object in the eye is experiencing abnormal vision
• Pain, redness or the sensation of an object in the eye persists after the object is removed

Keep in mind that sometimes an object can scratch your eye. This often feels as though the object is still in the eye. This sensation can sometimes take 24 hours to go away.

Laser eye surgery reshapes the transparent dome-shaped structure in the front of your eye (cornea) to correct vision problems (refractive errors). Laser eye surgery is a permanent change that reduces or eliminates your need to wear glasses or contact lenses.