Cataracts are a condition in the lens of the eye that leads to slow loss of vision.
This may begin with changes in how you see color — most often, yellowing or darkening of the colors around you — as well as haziness or blurriness, double vision in one eye, and spots of lost vision.
Proteins in the lens of the eye begin to break down and clump together, usually due to age, but also due to disease or eye trauma. These cause cataracts. By 80 years old, over half of American adults have either developed cataracts or undergone cataract surgery.
This is a very treatable eye condition, and this article can help you learn more about what cataracts are, why they form, how you can slow their progress, and what surgical procedures and artificial lens options are available to help you see clearly again. There are also new treatments being developed, including special eye drops. Cataract surgery is outpatient, and the majority of people who undergo this procedure recover most of their vision within months.
Table of Contents
What Is a Cataract?
A cataract is a change in the lens of the eye leading to cloudy spots or an opaque lens. This is a progressive condition that can take years to obstruct vision, but if left untreated, cataracts can lead to blindness.
The lens of the eye is located behind the iris. The lens is responsible for refracting light into the back of the eye, onto the retina, which processes images through the optic nerve and into the brain. When something is wrong with the lens, images of the world will not be transmitted well into the brain. This can lead to fuzzy, blurry, colorless, or doubled images, depending on what is wrong with the lens.
In the case of cataracts, proteins in the lens are damaged, leading to clumps that eventually obstruct vision. While the condition is painless, it can be frustrating as it develops, and it can eventually be debilitating.
Millions of people develop cataracts, typically starting after age 40, with most developing around age 55. By 80 years old, around half of American adults either have cataracts or have had cataract surgery. Cataracts will develop in both eyes, but one will typically get worse than the other and need more immediate attention.
For the most part, it takes years for cataracts to reach a point that they require medical treatment. Most optometrists and ophthalmologists will monitor the progress of a cataract in annual exams unless vision suddenly and rapidly changes. There are some lifestyle changes you can make to slow down the cataract’s progress, but ultimately, all cataracts will need surgery.
Fortunately, cataract surgery has a high success rate, and with a little time to heal and adjust, most people regain vision enough to go about their daily lives without intrusion. About 22.3 million Americans have cataracts at some point, making it one of the most common eye conditions in the country.
Symptoms of Cataract Development
There are a few symptoms of cataracts, which may initially seem like a different vision problem, but can be appropriately diagnosed by an optometrist or ophthalmologist. These symptoms include:
- Hazy or foggy vision.
- Blurry vision.
- Double vision in one eye.
- Lower intensity of colors, especially colors seeming more yellow.
- Increased sensitivity to light, especially bright lights.
- Trouble with night vision, especially driving at night.
- Change in the eye’s refractive error, such as nearsightedness or farsightedness.
If you have had a refractive error like myopia (nearsightedness), you may experience a sudden improvement in vision, followed by a worsening of vision. You may even be able to see the cataract in your eye, behind your pupil. It may appear like a milky white or yellowish spot.
Most cataracts are age-related, so it may be difficult to tell if you are developing a cataract or if your vision is changing in other ways due to age. Even after you have received a cataract diagnosis, your optometrist may simply strengthen the prescription for your glasses or have you wear different kinds of corrective wear until other symptoms of the cataract become too difficult to manage. Your optometrist may recommend wearing glasses with an antiglare coating, especially for night vision.
Different Types of Cataracts
All cataracts occur because of damaged proteins in the lens clumping together and obstructing vision; however, there are several kinds of cataracts that lead to different symptoms, have different root causes, and will look different in the eye.
- Nuclear cataract: This type of cataract forms in the center of the lens, often darkening as it spreads, leading to hazy, blurry, or yellowed vision.
- Anterior polar cataract: This is a dot near the center point of the front of the lens, which eventually spreads out.
- Cortical cataract: This kind is the opposite of nuclear cataracts, beginning on the outer edges of the lens and spreading inward, looking like spokes on a wheel.
- Lamellar cataract: This occurs in the layers between the nuclear and cortical parts of the lens, creating striations.
- Posterior capsular cataract: These cataracts form faster, and they are more likely to occur in younger people. They occur when proteins settle at the back of the lens and begin to form a hazy area. There are a few different types of posterior cataracts.
- Posterior subcapsular cataract: This involves a thin layer of clouding and protein clumps affecting the back surface of the lens.
- Posterior polar cataract: These are like the anterior polar cataract, but at the back of the lens rather than the front.
- Congenital cataract: These are formed in utero or just after a baby is born, and they are most often caused by illness or trauma during fetal development; however, in some instances, the cataract develops due to genetics.
- Trauma-induced cataract: Damage to the lens leads to damaged proteins clumping and forming cataracts, and if the eye is hit, diseased, under intense pressure, or undergoes surgery like LASIK, a cataract may form.
- Radiation cataract: This type of cataract forms after exposure to radiation, either in a radioactive area or after long-term exposure to UV radiation.
Causes of Cataracts
Most cataracts develop due to aging or injuries that change the functioning of your eye lens. Some risk factors that predispose to cataract formation include:
- Chronic diseases, including diabetes mellitus or glaucoma.
- Diseases during pregnancy, including toxoplasmosis, herpes simplex, rubella, syphilis, or cytomegalovirus.
- Excessive production of oxidants
- Trauma or accidents
- Exposure to UV radiation
- Radiation therapy
- Long term use of steroids and medications used to treat arthritis, lupus, and other health conditions
- Previous eye surgeries
- High blood pressure
- Excessive alcoholism
- Old age
- Family history of cataracts
How Are Cataracts Diagnosed?
There are several factors influencing whether or not you are at risk of developing cataracts.
- Family history
- Gender (Women may have a slightly higher risk than men.)
- Substance abuse history
- Sun exposure
- Other medical conditions
When you experience changes in your vision and you go for an eye exam, your optometrist will run a series of tests and ask you several questions to understand more abut your condition. Some of the diagnostics will include:
- Getting a patient history or updating an existing patient history about how vision has progressed and may be limiting current daily activities.
- Visual acuity measurements, such as the Snellen chart and other tools to determine the extent of refractive error, color change, eye shape change, and other issues that may be caused by the cataract or that may have led to the cataract.
- Slit lamp tests, allowing your optometrist to see into the back of your eye.
- Refraction error to determine how glasses or contact lenses can improve vision.
- Evaluation of the lens, using light and high magnification to illuminate the lens to see where proteins are clumping and diagnose the type of cataract that is forming.
- Evaluation of the retina to understand if there are additional diseases or damage that may be causing visual problems.
- Measurement of fluid pressure in the eye.
- Color and glare sensitivity testing.
Typically, your optometrist will notice the cataract during a routine exam, or your vision will change enough that you will need to see an optometrist for a diagnosis before your vision is severely impaired by the cataract. Most eye doctors will monitor the progress of the cataract before it becomes a very serious issue, so they will not immediately send you into surgery to replace the lens, but eventually, you will need to have your biological lens replaced with an artificial lens, called an intraocular lens (IOL).
Monitoring the progress of the cataract is the main approach to treatment until surgery is needed. Your eye doctor will change your glasses and contact lenses prescription to improve blurry vision and associated refraction errors as much as possible until your vision has become too obscured by the cataract. In some cases, you may receive special eye drops to widen the pupil, allowing more light through. These are mainly prescribed to young children to prevent extensive vision loss until they can undergo surgery.
If you receive a cataract diagnosis, you should speak with your eye doctor right away about surgery prospects and the process of monitoring your cataract’s development. Each person’s timeline is different, and your doctor can inform you about the next steps.
Surgery to Treat Cataracts
After your cataracts have progressed to the point that you can no longer safely perform normal, daily activities, your ophthalmologist will recommend surgery. There are a few types of cataract surgery, but they all ultimately remove the biological lens in your eye, which has become damaged, and replace it with an IOL. Types of cataract surgery include:
Small-incision cataract surgery.Using a microkeratome, this procedure involves making the smallest possible incision into the side of the cornea, the outer layer of the eye, in order to reach the lens. A tiny probe is then inserted to break up the damaged lens using ultrasound waves in a process called phacoemulsification. The pieces of lens are removed, and an IOL is inserted.
Extracapsular surgery.A somewhat larger incision is made in the cornea, so the lens can be removed in one piece. Then, the IOL is inserted.
All-laser surgery.This is similar to the small-incision surgery above, but instead of using a microkeratome, which is a type of bladed instrument, a laser is used. The laser may also be used to soften the lens before the probe breaks it up, reducing the overall impact of the sound waves, leading to easier removal and faster healing.
Eye surgeons typically remove cataracts from one eye at a time. If you have cataracts in both eyes that require surgery, your ophthalmologist will remove one, allow your eye to heal, and then remove the other.
There are side effects associated with cataract surgery, as there are for any surgical procedure. There is a minor risk of retinal detachment, for example. You may develop an infection or bleeding that does not stop. You may also develop a secondary cataract or otherwise experience vision loss.
These side effects are very rare, and medical professionals are investigating methods for improving surgical outcomes. The majority of people who undergo cataract surgery, most often after age 60, usually regain most of their vision and, with a little help from prescription glasses, can perform all kinds of normal tasks like reading, driving, typing on a computer, and enjoying long walks. About 90 percent of people who undergo cataract surgery report improved vision, making this outpatient procedure one of the safest and most effective surgeries in the United States.
The most common IOL implanted — because it is covered by health insurance — is the monofocal IOL. It may be made of silicon or acrylic material. This artificial lens does not focus well on different distances, so you will likely need contact lenses or glasses after your cataract surgery, so you can perform tasks close to your face and see distances clearly.
There are other types of lenses you may opt for, although you may be charged out of pocket for the cost.
Multifocal lensesThis type of IOL provides both near and far focusing at the same time, and it allows for clear vision more like your original, biological lens.
AccommodativeThese change shape inside your eye as you focus, acting much more like a natural lens.
Toric lensesThese are designed specifically for people with astigmatism, a refractive error that changes the shape of the eye itself.
Each of these lenses may be covered in part by health insurance, but the full cost is not likely to be covered unless there is a distinct medical need. If you are interested in these lenses, and your eye doctor has not recommended them for you, ask about the difference in cost and any difference in post-surgery outcome.
How Long Should You Rest After Surgery?
Interestingly, unlike other eye surgeries, recovering from cataract surgery is quick. Even though different patients have varying recovery times, most patients report improved vision after the first 24 hours. Nonetheless, you should plan three days off work to get enough rest. Simple diversions, such as reading, writing, watching TV, and walking, can help ease your recovery period.
While your eye will structurally heal from the surgery after approximately one month, it is best for your eye surgeon to determine when recovery is complete. As you recover, below are a few things to keep in mind during the first two weeks:
- Don’t drive immediately after the surgery
- Avoid heavy lifting and strenuous activities
- Don’t swim or shower with a hot tub to prevent infections
- Don’t rub your eyes after the surgery
- Avoid makeup, lotion, or face cream
- Prevent irritations by avoiding areas with dust, wind, dirt, or pollen
- Use sunglasses when out on bright days. You should do this for at least one year after surgery
Note that it is normal to feel some swelling and inflammation of the cornea the first days after surgery. Even if you don’t experience these complications, it is important to follow your doctors’ post-op directions.
Surgery Side Effect: Secondary Cataracts
Development of a secondary cataract is the most common side effect of cataract surgery. This is sometimes referred to as an after-cataract, and the medical term is posterior capsular opacification (PCO). This may develop months or years after cataract surgery, and it typically develops because not all of the diseased lens was removed in the original procedure. This leads to a portion of lens cells settling onto the back of the lens capsule and forming another cataract.
Symptoms of a secondary cataract mimic the first cataract, mostly with discolored, hazy, or blurry vision. This condition may develop weeks, months, or years after the cataract procedure, and it is the most common side effect associated with cataract surgery. Fortunately, it is very treatable.
While the first cataract surgery involves removing the lens, secondary cataract surgery is simpler. A procedure called YAG laser capsulotomy uses a laser to make a small hole in the capsule itself, allowing light to filter through your artificial lens, the new tiny hole, and onto the retina, clearing up vision. For some people who have multiple complicating conditions, this procedure may need to be performed several times over the years, but this is extremely rare.
Changes in Lifestyle to Slow Down Cataract Growth
Once a cataract forms, it will progress until vision is seriously impaired. However, there are a few steps you can take to slow down the progress of a cataract after it begins. Lifestyle changes include the following:
- Quit smoking.
- Reduce alcohol consumption or quit drinking.
- Avoid substances of abuse, including steroids.
- Wear UV-blocking sunglasses outside.
- Eat a healthier diet or take vitamin supplements to increase antioxidant consumption.
- Follow doctors’ orders regarding chronic illnesses like diabetes and blood sugar monitoring.
Medical professionals have identified several nutrients that may improve vision and reduce the risk of cataracts, including vitamin C, vitamin E, zinc, zeaxanthin, and lutein.
Potential Future Treatments for Cataracts
Researchers have made several breakthroughs that can change how cataracts are treated, with great potential that drug therapies will replace surgeries. As of now, international scientists have published peer-review research studies suggesting that lens optics develop from gestation, contrary to previous findings.
The team of researchers also found that aquaporin, a specific protein in the eye responsible for the passage of water in the lens, disrupts optical development, enhancing cataract development. While further research in this area is expected, proper management of aquaporin may promise the replacement of cataract surgery with drug therapies.
Another study found that a certain type of eye drop may slow the growth of cataracts. The research study into a chemical called Compound 29 found that it reversed age-related and hereditary cataracts in mice and in human lens tissue that had been removed during cataract surgery. However, there have not been further extensive studies on the eye drops.
For now, cataracts remain a very common, and fortunately very treatable, condition of the eyes.
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