Causes and Risk Factors of Cataracts

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Most people will eventually develop cataracts, which commonly occur due to the aging of the lens of the eye, causing it to become cloudy. Cataracts can develop in just one or both eyes.

For the most part, cataracts evolve over a long period of time—so slowly that you may not even notice your vision changing at first. Age-related cataracts tend to be seen in those over age 55. By ages 75 to 85, around half of people will have vision issues due to cataracts.

But cataracts can occur at any age, even in young infants, due to congenital conditions, medications, or trauma. Here’s what to know about what brings on cataracts and what may put you at greater risk for developing the condition.

Laura Porter / Verywell

Common Causes

Cataracts involve the lens of the eye, which focuses light rays on the retina at the back. Normally, the lens is clear. This allows light rays to easily pass through without scattering. But, when some of the proteins that make up the lens begin to break down, that can all change.

If lens proteins stick together, these can begin to block the light from getting through to the retina. This may start with just a small area that doesn’t yet affect vision. But with time, this will likely expand, making it more difficult to see, with vision becoming more blurry and colors less vibrant.

Some theorize that changes in the lens can be due to common insults to the eye. These can include environmental factors like too much sunlight, cigarette smoking, or even the impact of uncontrolled diabetes.

Other possible risk factors for developing cataracts can include:

  • Increasing age
  • Family predisposition
  • Sex: Women tend to be more likely to develop cataracts than men.
  • Ethnicity: Black Americans are more likely to develop cataracts and to have a visual impairment.

There are four different types of cataracts, and each has its own cause. These include:

  • Age-related cataracts: This is the most common type of cataract. These tend to occur as someone gets older. Further differentiation into types depends on where in the lens they occur. You may be told that you have a nuclear, cortical, or posterior subcapsular cataract.
  • Congenital cataracts: These may be present at birth or sometimes occur later during the first year of life.
  • Traumatic cataracts: One of these cataracts can come on at any time. This can occur when there is a blow or other injury to the eye. Protective eyewear can be most helpful in avoiding these.
  • Secondary cataracts: These can develop after taking certain medications, such as steroids. Or, diseases such as diabetes can be a predisposing factor.


Genes can play a role in the development of some cataracts, but while a number of genes have actually been identified, the list is far from complete. When it comes to congenital cataracts, heredity currently seems to account for between 8.3% to 25% of cataracts.

There is some thinking that not only is it necessary to identify the genes themselves that may be involved, but also the amount of damage caused by a mutation.

Congenital cataracts may be caused by a gene mutation that severely interferes with lens protein. Meanwhile, one that causes less severe interference with the same protein might play a role in an age-related cataracts.

Particularly with age-related cataracts, which don’t usually develop until you are in your 50s, it’s most likely that genes are just one factor. Also important can be environmental insults to an eye that may be genetically predisposed to developing cataracts.


While the eye is localized, there can also actually be a cardiovascular connection here. There’s some thinking that statin drugs that are used to stave off coronary artery disease may also help to keep cataracts at bay longer.

A February 2012 study, led by Donald S. Fong, MD, MPH, showed that in younger patients, ages 50 to 64, statins helped to quell cataracts when used long enough. But in older patients where these had already likely formed, using statins did not help.

Some theorize that antioxidant properties of the statins may have a protective effect. It also seems that younger cataract patients are more apt to later develop heart disease.

A July 2016 study showed a link here. Researchers think that the connection may involve inflammation, harmful compounds formed after sugar exposure, or exposure to too many oxygen-containing free radicals.

Lifestyle Risk Factors

While some factors, such as genetic predisposition, are out of your control, there are things you can do to help lower the risk of developing cataracts. The idea is to keep environmental factors from affecting lens proteins. Simple steps for you to try include:

  • Protect your eyes from the sun by wearing UVA/UVB-reducing eyewear, as well as donning wide-brimmed hats.
  • Avoid smoking.
  • Keep chronic conditions such as diabetes under control.
  • Maintain a healthy diet.

Some nutrients are more valuable than others for staving off or slowing down cataracts. Vitamins C and E are thought to provide an antioxidant effect, protecting the eye from damaging oxygen from free radicals.

You may try taking daily vitamins, or instead try to fill your diet with healthy food known to contain these. Some foods rich in vitamin C to consider putting on the list are:

  • Citrus fruits such as oranges and grapefruits
  • Strawberries
  • Papaya
  • Tomatoes
  • Green peppers

Likewise, the carotenoids lutein and zeaxanthin, which are found in the eye, may lower the risk of developing cataracts. Some foods high in these nutrients include:

  • Tangerines
  • Persimmons
  • Dark green leafy vegetables such as kale, collard greens, and spinach
  • Broccoli
  • Peas
  • Corn
  • Orange peppers

A Word From Verywell

By leading a healthy lifestyle, you can hopefully avoid some of the causes of cataracts and potentially avoid or at least delay the onset of the condition. If you develop a cataract, the good news is that cataracts can be easily and effectively treated before they significantly impair your vision and need to be removed.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. University of Michigan, Kellogg Eye Center, Cataract.

  2. American Optometric Association, Cataract.

  3. Johns Hopkins Medicine. Cataracts.

  4. Mount Sinai, Cataracts.

  5. American Optometric Association, Diet and nutrition.

  6. Shiels A, Hejtmancik JF. Genetics of human cataract. Clin Genet. 2013;84(2):120-127. doi:10.1111/cge.12182

  7. Fong DS, Poon KY. Recent statin use and cataract surgery. Am J Ophthalmol. 2012;153(2):222-228.e1. doi:10.1016/j.ajo.2011.08.001

  8. American Academy of Ophthalmology, Statins and the eye: making sense of the data.

  9. Hu WS, Lin CL, Chang SS, Chen MF, Chang KC. Increased risk of ischemic heart disease among subjects with cataracts: a population-based cohort study. Medicine (Baltimore). 2016;95(28):e4119.doi:10.1097/MD.0000000000004119

By Maxine Lipner
Maxine Lipner is a long-time health and medical writer with over 30 years of experience covering ophthalmology, oncology, and general health and wellness.