An Overview of Cataracts

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Cataracts are the leading cause of vision loss among people over age 55. They can make your vision appear fuzzy or blurry as if you are looking through a fogged-up, cloudy window. Cataracts can develop due to normal aging. Additionally, risk factors such as diabetes and smoking can also predispose you to cataracts.

Diagnosis of cataracts involves examinations that visualize the internal structures of your eye. Treatment can range from wearing stronger eyeglasses to surgical removal of the cataract, and sometimes cataract surgery includes replacement of the lens in your eye.


Cataracts can develop in one or both eyes. They are painless, and they don't cause any changes in the appearance of your eyes. Vision is not usually affected early on when cataracts are small. Cataracts usually worsen over time and can cause a gradual deterioration of vision.

The most common symptoms of cataracts include:

  • Blurred vision
  • Light sensitivity
  • Seeing halos around lights
  • Impaired night vision
  • Yellowing or fading of color vision
  • Double vision
  • Altered depth perception

Often, the vision changes are gradual, and you might need to have frequent changes in your eyewear prescription. This can be a clue that you are developing cataracts.


A cataract affects the lens of the eye. The lens is responsible for focusing light and for producing clear, sharp images. Your lens is a transparent structure that is mostly made up of water and protein fibers.

The entire lens is contained within a lens capsule. As the eyes age, protein and dead cells accumulate in the lens capsule, forming a cataract and causing the lens to become cloudy. Early on, a cataract may be a small, opaque spot. Over time, it may grow larger and cloud a bigger portion of your lens, making it harder for you to see.

With a cataract, the light that would normally be focused by the lens is scattered around because of the cloudiness, so vision is no longer clear and sharp.

Most older people develop some degree of lens clouding, which is a normal part of aging. However, if a cataract is left untreated, it can eventually lead to complete blindness.

Risk Factors

The biggest risk factor for developing cataracts is aging. Other risk factors include:

  • Diabetes
  • Eye surgery
  • A family history of cataracts
  • Smoking
  • Certain medications, such as steroids and statins (a type of cholesterol-lowering medication)
  • UV exposure
  • Radiation
  • Eye trauma
  • Congenital (present from birth or during early childhood)


Your doctor can perform a number of vision tests and detailed eye examinations to help diagnose a cataract. Usually, an ophthalmologist or an optometrist must do these tests for you because they have experience with visual assessment and because some of the tests require special equipment.

Tests you may need if you have a possible cataract include:

  • Visual acuity test: Your eye doctor will measure the sharpness of your vision by having you read letters on a chart from a distance.
  • Contrast sensitivity testing: This is an assessment of your ability to detect visual contrast, which can be altered due to glare caused by your cataract. Eye doctors consider contrast sensitivity testing to be a valuable measure of the quality of your vision.
  • Slit lamp exam: A slit lamp exam uses light and a microscope to examine the structures of your eye in detail. Your doctor will ask you to place your chin on the chin rest of the slit lamp. A light will then be directed at your eye. By looking through the slit lamp, especially when your pupil is dilated (with eye drops), your doctor can see the cataract and other eye problems.
  • Retinal exam: Using an ophthalmoscope, your doctor can carefully examine the inside of your eyes. Your doctor may use eye drops to dilate your pupils. This examination is typically used to examine the optic nerve and retina, but the lens can be visualized as well.
  • Tonometry test: This examination measures the pressure inside your eye, often using a small probe placed directly on the eye or an air puff test. While this test is not specifically designed to assess cataracts, it can identify other eye problems that cause visual deterioration, such as glaucoma.
  • Potential acuity test (PAM): This test measures how well you would see if you did not have a cataract. This helps you and your doctor know whether cataract surgery would improve your vision. A PAM test projects a visual acuity eye chart into the eye with a laser, by-passing the cataract. You can read the chart the same way you would read an eye chart on the wall. If your vision is read as 20/40 using a PAM exam, cataract surgery would be expected to give you 20/40 vision from that eye.

When you have vision loss and cataracts, it is important to keep in mind that you could also have other conditions contributing to your vision loss in addition to your cataract.

Types of Cataracts

The lens consists of three layers: the outer layer (capsule), the middle layer (cortex) and the inner layer (nucleus). There are three different types of cataracts, distinguished by the part of the lens affected.

  • Nuclear sclerotic: This is the most common type of age-related cataract. This type of cataract causes gradual yellow cloudiness and hardening of the nucleus of the lens. Changes in vision are usually gradual. As a nuclear sclerotic cataract develops, you may experience an improvement in your near vision before your vision deteriorates. Referred to as "second sight," this stage is usually only temporary.
  • Cortical: Diabetes is one of the leading risk factors for developing a cortical cataract. The cataract generally appears as a whitish, cloudy opacity in the cortex of the lens. These cataracts often resemble wheel spokes, pointing toward the front and center of the lens. Light tends to scatter when it hits the spoke-like opacities.
  • Posterior subcapsular cataract (PSC): These cataracts form in the back of the lens and usually affect one eye more than the other. PSC is an opacity that develops on the back surface of the lens. This type of cataract causes light sensitivity, blurred near vision, and glare and halos around lights. They are more common among people who have diabetes or who have taken steroids for extended periods of time.


Cataracts that are small and do not have a major impact on vision generally do not require treatment. Wearing stronger corrective glasses, using artificial tears, tinting lenses to reduce glare, and using sunglasses can help with many of your symptoms. However, if you have significant vision loss due to a large cataract, you may opt for cataract surgery.

Surgery is the only cure for cataracts. Cataract surgery involves removing the clouded lens and possibly replacing it with an artificial lens implant. Surgery is usually performed on one eye at a time. This is done to minimize potential complications. Cataract surgery is usually an out-patient procedure, and you should expect to go home on the same day of your procedure.

Eye Drops

You may have friends or family members who suggest Lanomax (lanosterol) eye drops as a treatment for your cataracts. This treatment is familiar to many people because it is used for the treatment of cataracts in some animals. But it is not approved for the treatment of cataracts in humans.

Cataract Surgery Basics

Before your surgery, you may be given a mild sedative and you will have eye drops placed in your eye to dilate your pupil. The skin around your eye and eyelid will be cleaned and sterilized. A sterile drape will be placed over your head and around your eye. Cataract surgery is typically performed with anesthetic eye drops.

Tiny incisions will be made in the peripheral part of your cornea, the clear dome-like structure on the front part of your eye. Next, the capsule will be opened. A small ultrasonic probe will be inserted into your eye. This probe will dissolve the cataract and the remaining material will be suctioned out.

A new, clear lens implant can then be inserted into your eye through the same small incision and positioned into place. The incision will be self-sealing and typically does not require stitches.

Common Types of Cataract Surgery

There are a few types of cataract surgery, and the best procedure for you depends on the size and location of your cataract.


Phacoemulsification (phaco) is the most common type of cataract removal procedure. An ultrasonic device vibrating at a high speed is inserted into the eye through a tiny incision. This device emits ultrasound waves that carefully soften and break up the lens, so it can removed by suction.

An artificial lens can then be inserted into the eye. Depending on the type of incision used, only one stitch (or none at all) may be required to close the wound. This cataract treatment is also called "small incision cataract surgery."

Extracapsular Cataract Surgery

This procedure is similar to phacoemulsification but a larger incision is made so that the lens can be removed in one piece. Several stitches or sutures may be required to close the wound. This procedure generally heals more slowly than small incision cataract surgery and may cause complications such as astigmatism.

Intracapsular Cataract Surgery

The entire lens and its capsule can be removed through a large incision. This method is generally reserved for large cataracts or eye trauma and can result in more complications and slower healing than surgeries that involve a smaller incision.

Laser Cataract Surgery

Laser cataract surgery uses a femtosecond laser, which produces a magnified, high-resolution image with a built-in optical coherence tomography (OCT) device. The laser creates an incision, the lens is broken into small pieces, and a new intraocular lens can be implanted.

After cataract surgery, your doctor may place an antibiotic ointment directly in your eye to prevent an infection.


It is okay to read, write or watch television right after your surgery, but you should wear sunglasses for the first few weeks when you are exposed to light, even indoors

Most people have some inflammation after cataract surgery, which can make your eye feel slightly gritty or scratchy for the first few days after the procedure. Your vision may be blurry due to the inflammation, pupil dilation, and antibiotic ointment.

You will be given a prescription and instructions for eye drops to use for the next couple of weeks after surgery. These eye drops are used to prevent infection and to manage inflammation.

You should avoid touching and rubbing your eye. You'll be instructed to wear an eye patch your first night after surgery to protect your eye. You should avoid bending over and lifting heavy objects for the first week or two following surgery.

Your doctor will most likely ask you to come in for several follow-up visits to monitor your recovery. After your first post-operative visit, you may be advised to wear a night guard patch for the next several nights.

Possible Complications

Cataract surgery is a safe procedure, with very few complications. However, as with any surgery, post-operative problems may develop.

Complications to look out for include:

  • Infection: An infection directly after cataract surgery can be very serious and is considered an eye emergency. If you have pain or redness, call your physician right away.
  • Inflammation: Some inflammation is expected after cataract surgery. Inflammation can cause light sensitivity, pain or achy eyes.
  • Swelling: Swelling in the back of the retina can occur. Although it requires attention, this usually resolves within a month or so.
  • Retinal detachment: If you see spots, floaters or flashes of light, call your doctor.
  • Posterior capsular haze: The capsule behind the new lens implant can thicken and become hazy 20 to 40 percent of the time after cataract surgery. This can make your vision blurry. A laser procedure known as "Yag capsulotomy" can remove this hazy capsule.


There are no specific medications or therapies used for cataract prevention, but several strategies can reduce your risk of developing cataracts.

Controlling your diabetes, not smoking, and wearing sunglasses can help prevent cataracts from developing or from worsening if you already have them.

Consuming antioxidants and Omega-3 fatty acids is associated with a lower risk of cataracts. This may be related to the actions of these dietary components, which neutralize harmful substances in the body.

A Word From Verywell

If you have blurry vision, it is important to schedule a comprehensive eye examination to determine the cause. Cataracts may be causing your vision problems, but other eye diseases can cause clouded vision as well. Your eye doctor will perform several diagnostic tests to check the overall health of your eyes. Many eye problems can be prevented or corrected if detected early. 

It is also important to know that just because you are diagnosed with cataracts, it does not mean you immediately need cataract surgery. Many people live with mild cataracts for years. However, if your cataract is causing substantial vision loss, there is no benefit to waiting before surgery. Advanced cataracts also carry a higher risk of complications during surgery.

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