Cataract

There is no blood test for cataracts. Doctors find them during a routine eye exam. Adults should have a dilated eye exam—where the doctor uses eye drops to widen the pupil (the dark opening in the center of the eye)—at least once every one to two years after age 60. Those with diabetes, a family history of eye disease, or other risk factors may need exams more often.

During a dilated exam, the doctor uses a slit lamp—a special microscope with a bright light—to look closely at the lens. This allows even small, early cataracts to be spotted before symptoms appear. The doctor will also check vision sharpness using an eye chart. Additional tests may measure how light scatters through the lens or how glare affects vision.

An eye doctor—either an ophthalmologist (a medical doctor who specializes in eyes) or an optometrist (a licensed eye care provider)—makes the diagnosis. In adults, cataracts are usually found during a routine eye exam, often before the person notices significant vision problems. In infants, cataracts may be detected during a newborn eye screening in the hospital or during well-child visits. Early cataracts can be subtle, so regular eye exams are important, especially for those with risk factors.

This is the basic eye chart test. The doctor asks the patient to read letters from a chart at a set distance. This measures how sharp, or clear, vision is at different distances. A significant drop in visual acuity may suggest a cataract or another eye condition.

A slit lamp is a special microscope that shines a narrow beam of intense light into the eye. It lets the doctor see the different layers and structures of the eye in detail, including the lens. This is the key test for identifying cataracts, including their type, location, and size.

The doctor places drops in the eye to widen (dilate) the pupil. With the pupil fully open, the doctor can see the entire lens and the back of the eye more clearly. This helps identify cataracts that might not be visible through an undilated pupil and allows the doctor to check for other eye conditions at the same time.

These tests measure how well a person sees under conditions of bright light or low contrast. They can help show whether a cataract is affecting functional vision—for example, the ability to drive at night—even when a standard eye chart test shows near-normal vision.

Cataracts cannot be cured with medicines, eye drops, or glasses. The only effective treatment is surgery to remove the cloudy lens. However, not everyone with a cataract needs surgery right away. In the early stages, updated glasses or brighter lighting may help enough for daily activities. Your doctor will help you decide when surgery is the right next step—usually when the cataract interferes with things that matter to you, like reading, driving, or working.

Cataract surgery is one of the safest and most commonly performed surgeries in the world. It is usually done as an outpatient procedure, meaning you go home the same day. The surgery is typically performed under local anesthesia (numbing medicine around the eye) so you are awake but feel no pain. Most surgeries take less than 30 minutes.

The most common method is called phacoemulsification. Your surgeon makes a very small cut in the eye, inserts a tiny probe that uses ultrasound (high-frequency sound waves) to break the cloudy lens into small pieces, and then gently suctions out those pieces. The lens capsule—the thin bag that held the natural lens—is left in place to hold the new lens.

After removing the natural lens, your surgeon places a clear artificial lens called an intraocular lens (IOL) inside the eye. This lens stays in place permanently and does not need to be replaced or maintained.

There are several types of IOLs. Your doctor will help you choose the right one based on your vision needs, eye health, and lifestyle.

• Monofocal IOL: the most widely used type. It is set to focus clearly at one distance—usually far away. You may still need reading glasses for close work. This lens is typically covered by insurance.
• Multifocal IOL: designed to allow clear vision at more than one distance—both near and far. This can reduce dependence on glasses but may cause more glare or halos around lights in some people.
• Extended depth-of-focus (EDOF) IOL: This is a newer type that provides a longer range of clear vision from near to far, with fewer halos than multifocal lenses.
• Toric IOL: corrects astigmatism (an uneven curve of the eye’s surface) along with cataract removal. Good for people who had significant astigmatism before surgery.
• Accommodating IOL: This is designed to shift position slightly inside the eye to improve focus at different distances, similar to how the natural lens works in a young eye.

Most people notice improved vision within a few days after surgery. Full healing usually takes four to six weeks. Your doctor will prescribe antibiotic and anti-inflammatory eye drops to prevent infection and reduce swelling. You will need to avoid rubbing your eye, swimming, and strenuous activity during the early recovery period.

Some people develop a condition called posterior capsule opacification (PCO)—sometimes called a secondary cataract—weeks, months, or even years after surgery. This happens when cells grow on the lens capsule that was left behind during surgery, making vision cloudy again. It is treated quickly and easily with a painless laser procedure in the office called a yttrium aluminum garnet (YAG) laser capsulotomy. Vision usually improves within 24 hours.