Medically reviewed by Joseph Christenbury, M.D.
A cataract is a gradual clouding of the lens in the eye that can cause a range of vision problems. The lens, along with the cornea transmits and focuses light onto the retina at the back of the eye. The lens is dynamic and can change its shape to focus at distance, intermediate and near objects.
The eye and its lens are made up mostly of proteins and water. As we age, the proteins may clump together creating areas of cloudiness and opacity that causes a cataract. People over the age of 50 are most at risk for age-related cataracts, the prevalence of which is expected to rise over the next 30 years. The National Eye Institute estimates that the number of Americans with cataracts will double by the year 2050.
There are many types of cataracts that can affect the eye. However, the most common types comprise four distinct groups based on where the formation of the obstruction begins:
- Nuclear cataract:Common type of cataract most frequently associated with aging. The nuclear cataract starts in the center of the lens (nucleus) and grows outwards. Symptoms of this cataract may include blurred vision, dulling of colors, glare and halos at night, acquired myopia (nearsightedness), and in some cases even double vision. As the cataract increases in density it may turn yellow or brown and cause a progressive increase in these symptoms.
- Cortical cataract: A cortical cataract begins its progression in the periphery of the lens and grows inward. Common symptoms from this cataract include blurred vision, prominent glare, halos, and light sensitivity. This type of cataract can occur in greater frequency in patients with diabetes.
- Posterior subcapsular cataract: This type of cataract originates at the very back of the lens and grows in a sheet-like pattern. This interferes with the direct pathway of light traveling through the lens to the retina and often causes difficulty reading, glare, halos, light sensitivity and decreased night vision. Posterior subscapular cataracts are also common in patients with diabetes.
- Traumatic cataract: Although typically associated with aging, cataracts can also develop as a result of an injury to the eye. This type of cataract can be composed of any combination of the three previously listed cataracts, or may have additional unique components. When speaking to your doctor, be sure to mention that you have had a history of trauma to your eye. This is important because during cataract surgery, the surgeon can take additional safety precautions during your surgery to maximize your chances of good vision postoperatively.
It’s also possible for cataracts to be present from birth. This rare type of cataract is referred to as a congenital cataract. If your child has congenital cataracts, surgery may be required in order to save vision. Determining when to have cataract surgery in the case of congenital cataracts is an open question. Performing cataract surgery on a newborn can be dangerous and run the risk of additional problems like glaucoma. However, waiting too long could permanently damage a child’s vision.
While there may not be any one element that is solely responsible for the development of a cataract, the following are the most common causes:
- Age: with aging comes an increase in several risk factors that can have a direct effect on cataract development, including type 2 diabetes, high blood pressure, long-term UV exposure, obesity and prolonged use of corticosteroids.
- Smoking: studies have shown that prolonged smoking can lead to an increased risk for developing cataracts.
- Previous eye-surgery or eye-injury: any damage or inflammation of the eye can make it more susceptible to cataracts, compounding the risk of cataracts in elderly people.
Whatever the exact cause, age is by far the biggest determining factor in developing cataracts, with the risks growing exponentially as people grow older. While only 42% of people between the age of 52-64 report vision problems due to changes in their lens the number increases all the way to 92% by the time people reach the age of 85
As cataracts develop, light is distorted when passing through the lens of the eye, thus causing visual impairment. A person with cataracts often describes their vision as looking through a dirty windshield of a car or a camera lens covered with a light film.
Common symptoms of cataracts may include:
- Blurred vision: vision may begin to blur, seeming as if you’re looking through a piece of cloudy glass or as if there is an irritant affecting your eyesight.
- Myopia:often in the beginning stages of age-related cataracts, near-sightedness may occur making objects in the distance seem blurry while images up close remain clear. Sometimes there is even an overall improvement in vision, known as second-sight, wherein the affected person’s vision actually becomes better for a short period of time before degenerating.
- Light sensitivity: both natural and artificial light may become glaring and make activities in sunny or well-lit areas difficult. Night vision will also be affected, making streetlights or oncoming headlights from cars appear more intense than before.
- Fading of colors: colors may also begin to appear less intense, especially in the blue spectrum.
If you notice vision changes or are having problems with light sensitivity make sure to schedule a visit with an ophthalmologist. The earlier you discover what the problem is, the more options you will have at your disposal for treatment, shortening your overall recovery time and giving you the best possible chance at continued clear vision.
A cataract is the clouding of the lens of the eye. Early form of cataracts may not pose a threat, but later it can impair vision which makes it difficult to read, drive a car, or see the expression on someone’s face.
Ophthalmologists and optometrists have several tests at their disposal to diagnose cataracts. These include:
- Visual acuity test:This test measures how well you can see at varying distances. Your doctor will ask you to read out loud a set of letters on an eye chart. This test is done using one eye to look at the letters while the other eye is covered. There are various sizes of the letters to determine whether your vision is impaired.
- Slit lamp: Another test that can be done is a slit-lamp examination, which allows your doctor to use light and magnification to see into your eye. These slits in the light allow the doctor to see tiny abnormalities within the structure of the eye. This is very helpful in determining what could be the cause for impaired vision.
- Pupil dilation: The doctor uses drops to dilate your eyes causing the pupil to increase in size allowing the doctor a clear view into the lens of the eye. With this examination (retinal exam), a doctor will be able to tell for sure if a cataract is impairing your vision.
- Dilated funduscopic exam: The doctor uses either the slit lamp or a headlamp along with a special lens to examine the back of your eye, called the retina. This can reveal other abnormalities that may impact the outcomes of your cataract surgery.
Cataract extraction is the primary course of action when treating vision loss caused by cataracts. Most doctors recommend this surgery when cataracts start to affect a person’s vision and quality of life. With cataract surgery, the lens of the eye is replaced with an artificial lens called an intraocular lens implant (IOL). In the rare cases when the surgeon does not deem it safe to implant an IOL, the cataract is removed and the patient is prescribed glasses or contact lenses to correct their vision.
There are essentially two types of cataract surgery to choose from: Traditional or laser.
Traditional Cataract Surgery – Phacoemulsification
Most cataract procedures today involve the use of a ultrasound device to break up the cloudy lens into small pieces, which are then removed by suction from the eye. This is known as phacoemulsification, or phaco. During phaco, a topical or local anesthetic is applied to the eye before treatment to minimize any discomfort or pain associated with the procedure. Once the cataract has been removed, an IOL is placed into the remaining lens capsule to restore vision. Depending on the type of IOL used, a larger incision may be required, which typically requires closing the incision with sutures. If using a smaller, foldable IOL, sutures are typically not needed.
This is performed as an outpatient procedure. Traditional cataract surgery is an outpatient procedure that usually requires less than 30 minutes to perform. Typically the patient spends only a few hours at the surgical center.
Laser cataract surgery, also referred to as a ‘bladeless’ technique, is a new form of surgery that uses femtosecond laser technology to treat cataracts. Harnessing the technology responsible for the advanced accuracy and safety of LASIK surgery, laser cataract surgery improves the precision of treatment. Laser cataract surgery can result in better outcomes for certain patients, particularly those with corneal astigmatism, than traditional surgical methods.,
Laser cataract surgery is in its infancy, having only been performed in the United States for the last several years. As such, not all eye surgeons offer it as a cataract treatment. However, there are at least four companies currently developing lasers specifically for use in this procedure. The FDA-approved LenSx femtosecond laser and Catalys femtosecond laser are the types that are most often used to perform laser cataract surgery.
As with other types of cataract surgery, this is an outpatient procedure. Patients are awake throughout, with anesthetic eye drops used to numb the eye. Prior to making any incision in the cornea, the laser creates an opening in the front of the lens capsule, called the capsulorhexis and uses laser energy to soften and break apart the cataract, making removal less difficult. This gives the surgeon access to the cataract once surgical instruments are inside the eye. Next, the surgeon creates an incision in the cornea to enter the front of the the eye. In traditional cataract surgeries, this incision is created with a handheld surgical blade. A benefit of laser-assisted cataract surgery is that the femtosecond laser is used to create the incision. Once the surgical instruments are inside the eye, the cloudy lens is removed in smaller pieces. Finally, the eye’s natural lens is replaced with an IOL to replace the eye’s natural lens. This step is performed in the same manner as in traditional surgery.
Laser cataract surgery can be safer than traditional surgery in some aspects of the procedure. However, as with all surgical procedures there is some degree of risk. Potential complications include infection, inflammation, or rotation of the artificial lens out of position, which may require additional surgery. The back of the implanted lens can also become cloudy, a condition known as posterior capsule opacity. While this leads some patients to believe their cataract has returned, it can be treated to restore the patient’s vision.
Cataract surgery is a safe and effective procedure, but there are some considerations that must be taken into account after treatment in order to ensure optimal recovery. You will not be able to drive immediately after cataract surgery, meaning that you will need to have someone there to drive you home. (Your doctor will evaluate your visual acuity in the day or two after cataract surgery to determine if you are safe to drive again.)
Most of the time, no stitches are required to close the incisions created during laser cataract surgery. Most patients take a few days to a week away from driving, working and other activities that may increase blood flow or pressure in the eye. Halos, glare or other vision disturbances may be experienced until the eyes have fully healed, which takes about a month.
Your cataract surgeon will prescribe medicated eye drops that are to be used to aid your recovery. Follow use instructions, which typically call for multiple drop applications each day for a week or two after surgery. You will also get a protective shield over the treated eye to avoid contact that can disrupt recovery. It’s imperative that you use this shield when sleeping in the week or two after surgery to avoid accidental contact. Lastly, be sure to avoid direct sunlight on the eyes. Your doctor may provide special protection glasses after surgery, otherwise just be sure to use your sunglasses whenever outdoors.
It’s not uncommon to experience some mild blurriness in your vision in the days after cataract surgery. You may also experience some eye redness. This is relatively common and not a cause for alarm. If this persists over the course of a week or more, be sure to contact your doctor.
Laser-assisted cataract surgery is typically more expensive than other cataract treatments. Additional costs associated with the laser equipment can add several thousand dollars to the cost of surgery, which is traditionally $2,000 to $5,000 per eye. It is likely that the laser-assisted method will add between $1000 and $2,500 to your total cost.
The cost of cataract surgery can also be impacted based on the type of IOL that you opt for.
There has been significant advancement in the field of intraocular lenses since they were first approved by the FDA in the early 1980s. Cataract surgery patients can now select from a variety of traditional and premium IOL options.
A traditional, monodical IOL is made of silicone or acrylic materials and designed to cater to vision across one focal distance. The patient can elect to have a monofocal IOL set to distance, near or intermediate vision range. Most monofocal IOL patients opt for distance vision and use reading glasses for near vision if needed.
Monofocal IOLs are the cheapest and most common variety used after cataract surgery.
Cataract surgery patients who want clear focusing across multiple distances will need to opt for a premium IOL.
Multifocal IOLs are an excellent option and offer clear vision across two focal distances: near and far. These are fixed focal points, meaning that vision between the two points will not be corrected.
Accommodative IOLs are similar to multifocal IOLs in that they cater to more than one focal point, but unlike multifocal lenses, they do not have fixed distance focal points. As the name implies, accommodative IOLs accommodate your vision across all distances. This is most like the natural lens of the eye in that it allows the patient to focus near, far and across all points in between.
Cataract surgery patients who also suffer from astigmatism may opt for a Toric IOL. Like multifocal IOLs, Toric IOLs can correct nearsightedness and farsightedness, while also correcting the irregular shape of the cornea causing astigmatism.
Cataract surgery is an incredibly popular procedure with a number of qualified surgeons capable of providing excellent results. Research your local cataract surgeon options online to evaluate the training and experience of the surgeons, read patient reviews and get a sense of the practice. Word of mouth is still a helpful aid, so be sure to ask around if your friends have had surgery to get feedback about their experience.
Once you have identified options, schedule consultations to meet with the surgeon(s) and learn more about your options. The surgeon will perform an eye exam and provide helpful feedback about your IOL options, costs and any other pertinent information that can aid the treatment process.
- Age Related Cataract: Author: Vicente Victor D Ocampo, Jr, MD; Chief Editor: Andrew A Dahl, MD, FACS
- AAO: What are Cataracts? Reviewed by Elena M Jimenez MD; Written by Kierstan Boyd (n.d.)
- NEI: Facts about Cataract (n.d.)