Last Updated: July 25, 2023

A cataract is a clouding of one or both lenses of the eye that can cause blurry vision, glare, poor night vision, double vision, and seeing colors that seem faded. Cataracts are a leading cause of blindness.

Cataracts falls under theEyes & Visioncategory.

What are cataracts?

A cataract is a cloudy area on the lens of the eye. Since the lens needs to be clear to function well, this opacity causes visual disturbances and, left untreated, can eventually result in blindness.[1]

What are the main signs and symptoms of cataracts?

As a cataract develops, it will start to cause visual disturbances like blurred vision, poor night vision, or difficulty differentiating colors. A halo may start to form around lights, especially at night. Some people also experience double vision and light sensitivity.[2]

How are cataracts diagnosed?

Cataracts are diagnosed with an eye examination. Although the symptoms are quite helpful in diagnosing a cataract, they can also be caused by other eye conditions, such as glaucoma. An ophthalmologist will dilate the pupil with eye drops and use a slit-lamp microscope to look at the lens and into the back of the eye.[3]

What are some of the main medical treatments for cataracts?

Currently, surgery is the only recommended treatment for cataracts. The surgeon will remove the cloudy lens and replace it with an artificial intraocular lens (IOL). The ophthalmologist will pick an IOL for each patient. In some cases, this procedure can even fix a refractive error that was previously corrected with corrective lenses.[4][5]

Have any supplements been studied for cataracts?

There is some evidence to suggest that caffeine may be helpful for preventing and treating cataracts. There is no clear answer yet, but higher coffee intake has been associated with lower cataract risk.[6][7] Vitamin supplements like vitamin E, vitamin C, and beta carotene have been studied as potential treatments for cataracts because they are antioxidants. However, the evidence does not support their use in cataract treatment yet. There is some research to suggest that the use of vitamin B supplements, especially vitamin B12, could play a role in cataract prevention.[8][8][9]

How could diet affect cataracts?

An increased intake of fruit and vegetables is associated with a slightly decreased risk of developing a cataract. A vegetarian or vegan diet may also decrease risk, although this effect might just be due to a higher vegetable intake, specifically a higher intake of legumes.[10][11][12][4]

Are there any other treatments for cataracts?

New agents are being studied in an attempt to develop a safe and effective medical treatment so that not everyone with cataracts will have to undergo surgery. Antioxidants like N-acetylcysteine and its precursors may help to reduce oxidation within the lens and prevent the formation of cataracts. Oxysterols such as lanosterol and 5-cholesten-3b,25-diol seem to stabilize proteins in the lens, and break up protein aggregates that make the lens cloudy. Uncertainty remains about the effective dosages, and the ability to reach the appropriate dosages for the lens through topical treatments like eye drops.[13][14]

What causes cataracts?

A healthy lens is a clear structure, allowing light to enter the eye. It focuses that light onto the retina, which enables clear vision. Cataracts are caused by proteins that clump together on the lens, making it cloudy. These protein aggregates get larger over time, and may also cause the lens to discolor. A cloudy and discolored lens will not filter light appropriately and therefore cause visual disturbances. The most frequent cause of this is normal aging, and most cataracts will occur in people over the age of 60. Other contributing factors include genetics, smoking, diabetes, and sun damage. A severe trauma to the eye can also cause a cataract to develop.[15]

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Update History
  1. ^Cataract(MedlinePlus)
  2. ^(National Eye Institute)
  3. ^What are cataracts?(American Academy of Ophthalmology)
  4. ^Zhang JH, Ramke J, Lee CN, Gordon I, Safi S, Lingham G, Evans JR, Keel SA Systematic Review of Clinical Practice Guidelines for Cataract: Evidence to Support the Development of the WHO Package of Eye Care Interventions.Vision (Basel).(2022-Jun-20)
  5. ^Cataract in the Adult Eye Preferred Practice Pattern(2016)
  6. ^Varma SDEffect of coffee (caffeine) against human cataract blindness.Clin Ophthalmol.(2016)
  7. ^Kronschläger M, Ruiß M, Dechat T, Findl OSingle high-dose peroral caffeine intake inhibits ultraviolet radiation-induced apoptosis in human lens epithelial cells in vitro.Acta Ophthalmol.(2021-Jun)
  8. ^Glaser TS, Doss LE, Shih G, Nigam D, Sperduto RD, Ferris FL, Agrón E, Clemons TE, Chew EY,The Association of Dietary Lutein plus Zeaxanthin and B Vitamins with Cataracts in the Age-Related Eye Disease Study: AREDS Report No. 37.Ophthalmology.(2015-Jul)
  9. ^Mathew MC, Ervin AM, Tao J, Davis RMAntioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract.Cochrane Database Syst Rev.(2012-Jun-13)
  10. ^Appleby PN, Allen NE, Key TJDiet, vegetarianism, and cataract risk.Am J Clin Nutr.(2011-May)
  11. ^Tina H T Chiu, Chia-Chen Chang, Chin-Lon Lin, Ming-Nan LinA Vegetarian Diet Is Associated with a Lower Risk of Cataract, Particularly Among Individuals with Overweight: A Prospective StudyJ Acad Nutr Diet.(2020 Dec 11)
  12. ^Fan H, Han X, Shang X, Zhu Z, He M, Xu G, Chen Z, Deng RFruit and vegetable intake and the risk of cataract: insights from the UK Biobank study.Eye (Lond).(2023-Mar-27)
  13. ^Lee BJ, Afshari NAAdvances in drug therapy and delivery for cataract treatment.Curr Opin Ophthalmol.(2023-Jan-01)
  14. ^Xu J, Fu Q, Chen X, Yao KAdvances in pharmacotherapy of cataracts.Ann Transl Med.(2020-Nov)
  15. ^National Eye Institute(January 2023)
Examine Database References
  1. Cataract Risk - Christen WG, Glynn RJ, Sesso HD, Kurth T, MacFadyen J, Bubes V, Buring JE, Manson JE, Gaziano JMAge-related cataract in a randomized trial of vitamins E and C in menArch Ophthalmol.(2010 Nov)
  2. Cataract Risk - McNeil JJ, Robman L, Tikellis G, Sinclair MI, McCarty CA, Taylor HRVitamin E supplementation and cataract: randomized controlled trialOphthalmology.(2004 Jan)