A cataract forms when the clear lens inside your eye becomes cloudy.1 It can affect vision and generally develops as people get older. Cataracts can develop slowly over many years or rapidly progress over a few months. In Canada, when a cataract is “ripe”, it can be easily treated with cataract surgery. 

Last Updated: March 27, 2023

Symptoms of Cataracts

Cataracts may affect vision in the following ways:

  • Blurry or foggy vision (for example it feels like there is a film covering the eye that does not go away with repeated blinking)
  • Double vision
  • Halos or ghost images
  • Dull or faded colour vision
  • Increased sensitivity to light and glare (for example to sunlight or oncoming headlights)
  • Trouble with night driving
  • Trouble seeing and reading at night (You need for extra lighting)

Causes of Cataracts1,3

There are many causes to cataracts, of which the most common is age. Cataracts are a part of the normal aging process and are most often found in those over the age of 60. When the proteins in the lens of the eye are disrupted and break down, it causes the lens to become cloudy leading to a cataract. 

Other causes of cataracts include UV damage, trauma, systemic conditions, certain medications, and congenital conditions. Prolonged UV light damage from not wearing sunglasses while being outdoors is a common cause of cataracts. Trauma to the eye including injuries, surgeries or radiation treatments can cause cataracts. Systemic conditions such as diabetes can cause cataracts as a buildup of sorbitol results in cloudiness of the lens. Individuals with diabetes should keep tight blood sugar control. Other systemic conditions that can cause cataracts include hypertension, obesity, chronic kidney disease, and autoimmune disease. Certain medications can cause cataracts to develop early, such as corticosteroids, chlorpromazine, amiodarone, phenytoin. In some cases, people are born with cataracts. These are called congenital cataracts. They may be inherited or result from an underlying health condition.

Video: Who is at risk for cataracts? | Dr. Tod McNab

Prevention and Screening of Cataracts1,4

Wearing UV protective glasses has been shown to be helpful in slowing down the development of cataracts. In individuals with diabetes, it is important to maintain tight blood sugar control. Some research evidence suggests taking antioxidants may be helpful in preventing cataract progression. Examples of antioxidant-rich food are berries, beans, pecans, prunes, and dark green vegetables. Quitting smoking may also prevent cataract development as smoking has been linked to cataracts. 

Cataracts are diagnosed with an eye exam. Visit your optometrist for your routine eye exams.

Treatment of Cataracts5

In the early stages of a cataract, symptoms are generally mild and vision is minimally affected. Your optometrist may prescribe updated glasses or contacts to give you the sharpest vision possible. As the cataract progresses, it may start to interfere with your daily activities and glasses may no longer work to improve your vision. At this time, your optometrist will refer you to an ophthalmologist who may recommend surgical removal of the cataracts. Find out more on how to prepare for cataract surgery.

In Canada, cataract surgery is one of the most common surgical procedures performed.5 It is an effective low-risk procedure. The process involves removing the cloudy lens from the eye and replacing it with a new clear lens implant. Generally, the lens implant will provide you with clear distance vision. Your near vision may still be blurry and will likely require reading glasses. Visit your optometrist one month after surgery to obtain your updated glasses prescription. 

Video: Do young people get cataracts? | Dr. Jeff Goodhew


CAO/Vision Institute cataracts brochure (PDF format)



  1. Lam D et al. Cataract. Nat Rev Dis. 2015;15014.
  2. Asbell PA et al. Age-related cataract. Lancet. 2005;365(9459):599-609.
  3. Ang MJ et al. Cataract and systemic disease: a review. Clin Experiment Ophthalmol. 2021;49(2):118-127.
  4. Kelly SP et al. Smoking and cataract: review of casual association. J Cataract Refract Surg. 2005;31(12):2395-2404.
  5. Olson RJ et al. Cataract treatment in the beginning of the 21st century. Am J Ophthalmol. 2003;136(1):146-154.
  6. Micieli JA et al. Cataract surgery. Can Med Assoc J. 2007;42(2):539-542.


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