Cataracts: Symptoms, Causes, & Treatment Options

By Zina Semenovskaya, MD
Medically reviewed checkmarkMedically reviewed
January 11, 2020

A cataract is a common eye condition in which the eye’s natural lens becomes cloudy and causes vision loss. Most cataracts are related to aging. This means that you will be at a greater risk of developing a cataract the older you are after turning 40. By age 80, 70% of white Americans, 53% of black Americans, and 61% of Hispanic Americans will have cataracts. Luckily, cataracts are generally easy to diagnose and surgical treatment is fast, safe and effective.

What Are Cataracts?

Each of your eyes has a natural lens which bends or ‘refracts’ the light rays that enter your eyes. It is situated behind your iris, the colored part of your eye. As light comes into the eye, your lens focuses it so that it produces clear, sharp images on your retina, the light-sensitive membrane at the back of your eye that works like the film in a camera.

To be able to see properly, the eye’s lens should be clear. If you develop a cataract, the lens becomes cloudy. Since a cataract blocks and scatters the light rays entering the eyes, the lens can no longer focus a sharp image on your retina and your vision becomes blurry, hazy, or dull. People with cataracts describe their vision as if they were looking through a foggy or dusty car windshield.

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Cataract stages

As a cataract develops, it slowly becomes denser and involves more of the lens area. This causes a gradual decline in vision which in later stages cannot be corrected with glasses. Cataracts can develop in both eyes but not necessarily at the same rate, so you may experience different degrees of vision loss in each eye. Although this condition normally affects older people, anyone can develop a cataract in one or both eyes.

Types of Cataracts

There are three common types of age-related cataract depending on where on the eye’s lens they occur. Cataract types include:

  • Posterior subcapsular cataract: This is a cataract that affects the back of the eye’s lens where a small, opaque area begins to form right in the path of light. This means you will start to find it difficult to read and see properly when you’re in brightly lit surroundings. You may also see glares or halos around lights at night. This type of cataract tends to get worse faster than other types of cataracts and is more common in people with diabetes or those taking high doses of steroid medications.
  • Nuclear cataract: This is a cataract that forms deep in the central zone, or nucleus, of the eye’s lens. At first, you may become more near-sighted and even find it easier to read. However, over time, the cataract progresses, with the lens turning yellow or even brown. This may mean that in addition to progressive vision loss, you may find it difficult to differentiate between shades of color.
  • Cortical cataracts: This is a cataract that occurs in the ‘cortex’ of the eye’s lens. This is the part of the lens that surrounds the central nucleus. It starts as white, wedge-like opacities or streaks on the outer edge of the lens which then work their way to the center of the lens and interfere with light passing through the lens center.

What is the difference between nuclear sclerosis and cataracts?

Nuclear sclerosis is when the central part of your eye’s lens, the nucleus, becomes cloudy, hard and yellow with aging. Unlike nuclear cataracts, the cloudiness does not block light hitting the retina at the back of the eye and there is no serious loss of vision or treatment needed.

Congenital cataracts

Some people are born with cataracts or develop them in early childhood; these are called congenital cataracts. The degree of severity of these cataracts varies, and they may not severely affect your vision. This type of cataract may be due to genetic factors, from an infection or trauma that occurred when still in the womb, or due to certain medical conditions. The treatment is the same as for other types of cataracts and generally involves surgical removal of the lens and replacement with a new one.

Cataract Symptoms

What are the first sign of cataracts?

Cataracts generally develop slowly over time, initially only mildly affecting vision and then gradually worsening.

Can you feel a cataract?

You may have a cataract if you have the following signs and symptoms: 

  • Clouded, blurry or dimmed vision
  • Progressive difficulty seeing at night
  • Being extra sensitive to light and glare
  • Requiring more light for reading and other daily activities
  • Noticing “halos” around lights
  • Needing frequent prescription changes for eyeglasses or contact lenses
  • Fading or yellowing of colors
  • Cloudy appearance to the lens portion of your eyes

What Causes Cataracts?

Cataracts are most commonly caused by the normal changes to your eyes as you age. Around age 40, the lenses in your eyes thicken and become less flexible and transparent. The proteins in your eyes lenses, which are normally arranged in a precise way to keep them clear and allow light to pass through, start to break down and clump together. This causes small areas within the lenses to become cloudy, though you may not notice any significant changes in your vision for years.

Cataracts which are not related to aging can occur in younger people and sometimes develop much faster, depending on their cause. ‘Secondary’ cataracts are a result of other medical conditions, such as diabetes, or as a side effect of medications, including corticosteroids or diuretics. They may also develop as a complication of surgery or from exposure to toxic substances, ultraviolet light, or radiation. You can also develop a ‘traumatic’ cataract if you’ve sustained an injury to your eye. Finally, some people are born with or develop in childhood a ‘congenital’ cataract, which can be genetic or caused by an infection, injury, or poor development in the womb.

How Are Cataracts Diagnosed?

In order to make the diagnosis, your doctor will obtain a comprehensive history and perform an eye exam. They may also refer you to an ophthalmologist—an eye specialist—who can perform one or more of the following tests:

  • Visual acuity test: This is a basic vision test to measure how well you can read a series of progressively smaller letters on an eye chart. Your eye doctor can then determine if your vision has deteriorated recently, and to what degree.
  • Slit-lamp examination: A slit lamp is a specialized piece of equipment used to closely examine your eyes by magnifying sections of your eye’s cornea, iris, lens, and the space between your iris and cornea.
  • Retinal exam: Your eye doctor will put drops in your eyes to dilate your pupils so that he or she can more easily examine the retina at the back of your eyes. This can be done using a slit lamp or an ophthalmoscope. 

Cataract Treatment Options

Home treatments

Early on, you may be able to adjust your daily routines to mitigate mild vision loss due to cataracts. These can include using brighter lights and magnifying glasses when working and reading, wearing anti-glare sunglasses, and avoiding driving at night.

New glasses or contacts

After you have been diagnosed with a cataract, you may still be able to see sufficiently well with prescription glasses or contact lenses.

Cataract surgery

If your cataracts are too advanced to be corrected with glasses or contacts and they are starting to significantly affect daily activities, such as reading or driving, it may be time to consider surgery. This is especially true if you have another medical condition, such as diabetes, which will speed up the progression of your cataracts. Cataract surgery is the standard treatment for cataracts, and it is also one of the most common eye surgeries, with more than three million Americans undergoing the procedure each year.

Cataract operations are quick, routine procedures performed under local anaesthetic by a trained eye surgeon. This means your eyes will be numbed but you will be awake during the procedure and will not need to recover from a general anaesthetic. You can therefore have cataract surgery as an out-patient and go home the same day.

During this very common procedure, the surgeon will remove your eye’s natural lens and replace it with a clear man-made one called an intraocular lens. If you have other eye problems that preclude the placement of the artificial lens in your eye, your surgeon will remove your natural lens with the cataract and your vision will then be corrected with prescription eyeglasses or contact lenses.

There are two main surgical techniques for removing your natural lens. The first technique is to use very small cuts to remove the lens. The second approach is called phacoemulsification cataract surgery. In this procedure, an ultrasonic device is used to break up and then remove the lens with a cataract. Either way, your surgeon will then immediately replace your natural lens with an artificial intraocular lens.

Cataract operations are extremely successful, with more than 98% of people reporting significantly improved vision according to the American Society of Cataract and Refractive Surgery. One study of more than 200,000 patients reports that 99.5% of them had no serious complications following cataract surgery. As with all surgeries, there is some risk of infection and bleeding. Your eyes will feel uncomfortable for a few days after cataract surgery, but should be fully healed within several weeks. If you need an operation in both eyes, you will need to have them spaced out so that you are fully recovered from your first cataract surgery before having your second procedure.

Who Is at Risk for Cataracts?

There are many factors that can increase your risk of developing a cataract. Risk factors besides getting older include:

  • Having diabetes
  • Excessive sun exposure
  • Smoking
  • Obesity
  • High blood pressure or hypertension
  • A previous eye injury, infection or surgery
  • Prolonged use of corticosteroid medications
  • Taking statin medications to reduce cholesterol
  • Drinking excessive amounts of alcohol
  • A family history of cataracts
  • Living at high altitude
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Cataract Prevention

There are some limited things that you can do to prevent the formation or progression of cataracts. Unfortunately, there is no medical treatment to prevent cataracts.

The main way to prevent cataracts is through making healthy lifestyle choices. Medical research has shown that a balanced diet rich in fruits and vegetables with many beneficial vitamins, minerals and antioxidants can maintain the health of your eyes and help prevent cataracts. Other steps you can take include not smoking and minimizing alcohol use. If you have diabetes, make sure that it is being well controlled through diet and medication. Medical research has shown that if you have type 2 diabetes, you can lower your risk of cataracts by almost 20% if you lower your HbA1c level by just 1%. Reducing exposure to ultraviolet light by wearing sunglasses is also helpful.

International medical guidelines recommend that adults have an eye examination every two years and annually after the age of 50. Eye examinations can help detect cataracts and other eye problems at their earliest stages.

When to See a Doctor

You should see an eye doctor if you notice any changes in your vision. Your doctor will carry out a series of eye tests, as described above, to evaluate the cause of your decreased vision. If you are diagnosed with cataracts, your eye doctor can recommend treatment options.

What will happen if a cataract is left untreated?

Although cataracts do not require emergency surgery, significantly delaying a corrective procedure can adversely impact your quality of life. Speak with your eye doctor about the treatment options that would be best for you.

How K Health Can Help

Do you suffer from vision loss that may be due to a cataract, or another problem with your vision?

Download the K Health app and speak with one of our doctors today. They can help review your symptoms and recommend the next steps that you should take for follow up and treatment.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Zina Semenovskaya, MD

Dr. Semenovskaya specializes in emergency medicine, and received her medical degree from Weill Cornell Medical College. She is currently the medical director at Remote Emergency Medicine Consulting, LLC and splits her time working clinically as an emergency medicine attending in California and Alaska. She is the first of our doctors to be fluent in Russian.