A cataract is a gradual clouding of the lens in the eye that can cause a variety of visual defects and losses. (1)
The lens, located in the front part of the eye, transmits and focuses light onto the retina at the back of the eye. The lens is dynamic and can change its shape to focus on objects at various distances. 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 condition is what is referred to as a cataract.
The process of cataract formation usually begins sometime around age 40, when eye proteins begin breaking down. However, the process is usually very gradual, and most people do not begin noticing changes in their vision from it until after age 60. (2)
Cataracts are very common. By age 80, 70% of whites in the U.S. have cataracts, along with 53% of blacks and 61% of Hispanic Americans. The prevalence of cataracts is expected to rise over the next 30 years. The U.S. National Eye Institute (NIH) estimates that the number of Americans with cataracts will double by the year 2050. (2)
There are a number of types and classifications of cataracts, including:
Nuclear cataracts: these are the most common type of cataract. 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, halos at night, acquired myopia (near-sightedness), and in some cases even double vision. As the cataract increases in density it may turn yellow or brown and cause a progressive interference with vision.
Cortical cataracts: these begin in the periphery of the lens and grow 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 people with diabetes.
Posterior subcapsular cataracts: these originate at the very back of the lens and grow 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. Vision loss tends to come on rapidly, often within months. Posterior subcapsular cataracts are also common in people with diabetes.
Anterior subcapsular cataracts: as the name suggests, these cataracts form in the front (anterior) part of the lens. They are often brought on by an eye injury, or eye swelling. They are also associated with a skin condition known as atopic dermatitis.
Traumatic cataracts: these develop as a result of an eye injury. This type of cataract can be composed of any combination of the previously listed cataract types, or may have additional unique components. They may appear shortly after the injury, or years later. When speaking to your doctor, be sure to mention it if you have a history of trauma to your eye. This is important because during cataract surgery, the surgeon can take additional safety precautions to maximize your chances of good vision postoperatively.
Congenital cataracts: this rare type of cataract is present from birth or forms in childhood. They may be caused by genetic defects, or by maternal illnesses during pregnancy, such as rubella. Often they are small or located away from the center of the lens, so they do not affect vision much. However, if they block the vision they could impair the brain’s ability to learn to see, and must be surgically removed.
The vast majority of cataracts are age-related; they are simply a side effect of the ageing body. However, there are other risk factors that can contribute to their development, including: (3)
- Family history – there is a genetic component to cataract development.
- Sun exposure – spending time in the sun without adequate eye protection contributes to the development of cataracts. This is why you should only wear sunglasses that have UV protection.
- Previous eye surgery or eye injury – any damage or inflammation of the eye can make it more susceptible to cataracts.
- Radiation treatments near the eyes – this includes radiation therapy anywhere on the upper body.
- Certain medical problems – such as diabetes, obesity, and high blood pressure. Note that these conditions become more prevalent as people age.
- Use of certain medications – particularly corticosteroids.
- Education – higher education levels are associated with lower risk.
- Refraction – near-sightedness (myopia) carries a higher risk of cataracts than does far-sightedness (hyperopia).
- Multivitamin use – specifically, the use of Centrum appears to reduce the risk of cataract formation.
As cataracts develop, light is distorted when passing through the lens of the eye, thus causing visual impairment. People with cataracts often describe their vision as looking through a dirty windshield of a car or a camera lens covered with a film. Cataract symptoms typically develop very gradually, and the cataracts may be well developed by the time they are noticed. 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 a brief overall improvement in vision, known as “second-sight,” where the 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.
- Reduced night vision – it becomes harder to see at night, and the there is increased sensitivity to light, such as from streetlights or oncoming vehicle headlights.
- Fading of colors: colors may also begin to appear less intense, especially in the blue spectrum.
- Changed appearance of the eye – the lens of the eye may begin to have a yellow- or brown-tinged appearance.
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.
Ophthalmologists and optometrists have several tests at their disposal to diagnose cataracts. These include:
Visual acuity tests: These measure 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 examination: This involves using a “slit-lamp” – which is a type of microscope specially designed for looking at the front part of the eye – to examine your eye under magnification with good lighting. Slits in the light allow the doctor to see even tiny abnormalities within the structure of the eye.
Pupil dilation: The doctor uses special drops to dilate your eyes causing the pupil to increase in size, giving the doctor a clear view into the lens of the eye. With this examination, the doctor can also get a good look at the retina (fundoscopic exam) to look for other problems that may be affecting your vision.
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 vision and quality of life.
With cataract surgery, the lens of the eye is replaced with an artificial lens called an intraocular lens (IOL) implant. 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 an 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. (4) 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 usually not needed. (4)
This is performed as 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
Laser cataract surgery, also referred to as the “bladeless” technique, is a new form of surgery that uses femtosecond laser technology to treat cataracts. (5)
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 than traditional surgical methods for certain patients, particularly those with corneal astigmatism. (5)
Laser cataract surgery is in its infancy, having only been performed in the U.S. 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.
As with other types of cataract surgery, this is an outpatient procedure. Patients are awake during the procedure, requiring only anesthetic eye drops 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 easier. (5)
Next, the surgeon creates an incision in the cornea to enter the front of 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 small pieces.
Finally, the eye’s natural lens is replaced with an IOL. This step is performed in the same manner as in traditional surgery.
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.
Many patients report clear vision within a few hours after the procedure. But each patient heals differently, and you may need as long as a week or more before you can see images in their sharpest focus.
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 it is safe for you 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. These typically require 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 is imperative that you use this shield when sleeping in the week or two after surgery to avoid accidental contact.
It is important to avoid direct sunlight on the eyes following cataract surgery. Your doctor may provide special protection glasses after surgery, otherwise just be sure to use your sunglasses whenever outdoors.
It is common 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 is also largely based on the type of IOL that you opt for.
There have been significant advancements 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.
Traditional (monofocal) IOLs
A traditional IOL is made of silicone or acrylic and designed to cater to vision at one focal distance; as such, they are known as “monofocal.” These can be chosen as either for near or distance vision. Most people opt for distance vision and use reading glasses for near vision if needed. Traditional monofocal IOLs are the cheapest and most commonly used variety for cataract surgery.
Premium (multifocal and accommodative) IOLs6
Cataract surgery patients who want clear focusing across multiple distances will need to opt for a premium IOL. Multifocal IOLs offer clear vision at two focal distances, near and far; unfortunately, 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.
Cataract surgery patients who also suffer from astigmatism may opt for a Toric IOL. Like multifocal IOLs, Toric IOLs can correct near-sightedness and farsightedness, while also correcting the irregular shape of the cornea that causes astigmatism. These are considered to be a premium lens.
Cataract surgery is a highly popular procedure with a large number of qualified eye surgeons capable of providing excellent results.
It is wise to research your local cataract surgeon options online to evaluate the training and experience of the surgeons, read patient reviews, and get a sense of their practice. Word of mouth may also be helpful, so be sure to ask your friends who have had cataract surgery to get feedback about their experience.
Once you have identified options, schedule a consultation to meet with the surgeon 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.
Contact an experienced ophthalmologist near you.
- National Eye Institute (NIH). (2019). Cataracts. Retrieved from https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/cataracts
- National Eye Institute (NIH). (2019). Cataract data and statistics. Retrieved from https://www.nei.nih.gov/learn-about-eye-health/resources-for-health-educators/eye-health-data-and-statistics/cataract-data-and-statistics#:~:text=Projections%20for%20cataract%20(2010%2D2030,million%20to%20about%2050%20million.
- Chang, J.R., Koo, E., Agrón, E., Hallak, J., Clemons, T., Azar, D., et al. (2011). Risk factors associated with incident cataracts and cataract surgery in the Age-related Eye Disease Study (AREDS): AREDS report number 32. Ophthalmology, 118(11), 2113–2119. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3178670/
- Davis G. (2016). The evolution of cataract surgery. Missouri Medicine, 113(1), 58–62. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139750/
- Vasquez-Perez, A., Simpson, A., & Nanavaty, M.A. (2018). Femtosecond laser-assisted cataract surgery in a public teaching hospital setting. BMC Ophthalmology, 18(1), 26. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5797358/
- Zvorničanin, J., & Zvorničanin, E. (2018). Premium intraocular lenses: The past, present and future. Journal of Current Ophthalmology, 30(4), 287–296. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6276729/