Age-related cataracts usually take decades to cause blindness. But certain cataract types can cause vision loss more quickly.

Cataracts usually develop in older adults. They remain a leading cause of blindness in many countries despite improvements in treatments.

Age-related cataracts usually take decades to cause blindness, but other types of cataracts can cause vision loss to happen more quickly.

This article explores how cataracts lead to blindness and how long complete vision loss can take if cataracts aren’t treated effectively.

Over time, the lens of your eye can become clouded simply from environmental and lifestyle strains. This is known as oxidative stress.

In particular, this lens clouding is caused by clumps of proteins that build up over time, preventing light from passing through the lens. The breakdown of these proteins that collect in your eye speeds up after age 40. This is why cataracts typically form at this age and beyond.

By age 80, most adults have at least some degree of cataracts.

The most common symptoms you might notice as cataracts begin to develop include:

  • blurred vision
  • halos of light around objects
  • faded colors
  • sensitivity to bright lights
  • poor night vision
  • double vision

Although cataracts can sometimes develop in children, age-related cataracts are the most common form. They start to develop in adults ages 45–50 years old.

As clumps of damaged proteins build up in your eyes, cataracts can grow larger and cause more vision problems.

In the early stages, you might not realize you have cataracts. Age-related cataracts can form so gradually that you might not think much of your vision changes.

As your vision worsens, or particular areas of vision loss become more noticeable, your eye doctor might diagnose cataracts.

Age-related cataracts are the most common type. They usually take decades to cause blindness, but other types of cataracts can cause vision loss to happen more quickly.

A traumatic cataract is one type of cataract that can cause blindness to develop more quickly.

Traumatic eye injuries affect about one-fifth of adults during their lifetime. Eye injuries when blunt, penetrating trauma damages lens fibers can lead to traumatic cataracts instantly or in the weeks or months after the injury occurred.

Radiation from sun damage or medical treatments can also lead to cataracts. Vision loss from radiation cataracts can happen more quickly than from age-related cataracts, but they still take longer to develop than traumatic cataracts.

Pediatric cataracts are another form of cataracts. They are usually present at birth or form in the first few weeks of life.

Genetic factors cause pediatric cataracts. If these cataracts are large enough at birth, doctors remove them quickly to prevent ongoing vision problems or blindness.

Smaller cataracts can usually be monitored over time and may never cause significant vision problems.

You can’t stop the aging process, but you can take steps to protect your vision throughout your life.

Some things you can do to protect your vision and prevent cataracts that could lead to blindness include:

  • wearing sunglasses or hats to protect your eyes from the sun and other forms of radiation
  • using protective eyewear when performing activities or work where there is a high risk of traumatic injury
  • avoiding smoking cigarettes or exposing your eyes to high levels of air pollution
  • eating a balanced diet rich in fresh fruits, vegetables, and healthy oils
  • limiting alcohol consumption

Other factors that can lead to cataracts include:

Cataract treatment has come a long way. Surgery can typically treat cataracts before blindness develops.

Today, blindness from cataracts is most common in countries where people have more difficulty accessing or paying for vision care.

If lens clouding from a large cataract is the only cause of vision loss, removing the cataract can reverse blindness. Cataracts are usually treated with surgery that removes the natural lens and replaces it with a new artificial lens.

What happens if you don’t remove cataracts?

The effect of leaving a cataract in your eye depends on its size and how much your vision is affected. Small cataracts might not cause any noticeable symptoms. Or they can cause subtle changes, like color vision loss or halos of light around certain objects.

If your cataract is so large that it blocks most of the light that passes through your lens, you could experience severe or total vision loss in one or both eyes.

At what stage should cataracts be removed?

Cataract removal is usually planned based on symptom severity. In most cases, your eye doctor will watch the development of your cataracts over time. They may not recommend surgical removal and lens replacement until the cataract is making it difficult to do your regular activities, like reading or driving.

What happens if a cataract bursts?

A cataract can break during surgery. This is one of the more common complications of cataract surgery.

If the capsule that holds your cataract breaks during surgery, it may become more difficult to completely remove the cataract and replace your lens during a surgical procedure.

Cataracts usually develop slowly as we age. Some types of cataracts, like those caused by traumatic injuries or radiation treatments, can develop more quickly. Large cataracts left untreated can cause blindness by blocking the flow of light into your eye.

If you have cataracts, your eye doctor will watch them over time. Doctors typically recommend removal when cataracts become large enough to disrupt your regular activities.

Cataract removal and lens replacement can cure vision loss that is strictly caused by a large cataract. As with any procedure, there are risks and benefits to consider. Talking with an eye doctor can help you decide what’s best for you and your vision.