A cataract is a clouding of the natural lens inside the eye, which is typically clear. Cataracts are a major cause of blindness worldwide, but doctors can surgically remove them to restore a person’s vision.

The clouding of a cataract interferes with the passage of light through the lens to the retina at the back of the eye, leading to blurred or hazy vision.

Cataracts can occur in one or both eyes and often develop slowly over time, although the rate of progression can vary between individuals.

This article looks at cataracts as a cause of vision loss, including the typical rate of progression and treatment options.

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Without treatment, cataracts can cause significant vision impairment, but they do not necessarily lead to complete blindness in all cases.

The process by which cataracts affect vision involves the clouding of the eye’s natural lens, which gradually reduces the amount of light that can pass through to the retina.

This clouding can cause a variety of visual disturbances, including the following:

  • blurry or hazy vision
  • difficulty seeing in low-light conditions
  • increased sensitivity to glare
  • changes in color perception

Can cataracts cause sudden blindness?

While cataracts can significantly affect a person’s vision and daily life, they generally do not lead to sudden or total blindness.

Someone could have another underlying eye condition, such as advanced glaucoma or retinal problems, that could cause sudden vision loss or worsening visual symptoms.

Dense cataracts can make it harder to diagnose these underlying conditions because the cloudy lens obscures the eye.

The rate of vision loss with cataracts can vary significantly from person to person. Several factors influence how quickly cataracts progress and affect an individual’s vision, including:

Generally, cataracts develop slowly, and people often experience subtle changes in vision initially. However, while some individuals may live with cataracts for many years with only mild vision changes, others may experience a more rapid decline in vision.

Recognizing cataracts

In the earliest stages, cataracts may not cause any noticeable symptoms. However, over time, people typically experience blurred or cloudy vision, increased sensitivity to glare, and difficulty seeing at night.

These symptoms can progress gradually, making it necessary to update eyeglasses or contact lens prescriptions more frequently.

Recognizing the signs of cataracts and seeking regular eye exams with an eye care professional is important. Early detection allows for monitoring and timely intervention when cataracts start to affect a person’s vision and quality of life significantly.

Most people seek medical attention when they notice significant vision problems, regardless of the cause.

As a result, healthcare professionals are often able to diagnose and treat cataracts early before they progress to a point where they would cause complete blindness.

The only fully effective treatment for cataracts is surgical removal. However, people may be able to temporarily manage them with changes to their eyeglasses or contact lens prescriptions.

Cataract surgery is a safe and common procedure that can significantly improve vision by removing the clouded natural lens and replacing it with an artificial intraocular lens (IOL).

Cataract surgery (phacoemulsification)

Cataract surgery is the most common treatment for cataracts. The procedure involves the following steps:

  • A healthcare professional administers anesthesia or anesthetic eye drops to numb the eye.
  • They make a small incision in the eye to access the clouded lens.
  • To break up and remove the cloudy lens, doctors may use ultrasonic phacoemulsification or laser technology.
  • An artificial IOL replaces the natural lens, providing clear vision.
  • The incision is typically self-sealing, eliminating the need for sutures in many cases.

Sometimes, after cataract surgery, the capsule behind the IOL may become cloudy, causing a condition called posterior capsule opacification.

A YAG laser capsulotomy is a noninvasive procedure to create an opening in the cloudy capsule, restoring clear vision.

People need to speak with their doctor if they notice changes in their vision, such as:

  • blurred or cloudy vision
  • reduced contrast sensitivity
  • increased sensitivity to glare
  • difficulty seeing at night

Cataracts may cause these symptoms, or they may be unrelated, but consulting an eye doctor allows them to monitor a person’s vision and diagnose the underlying cause.

In the earliest stages, cataracts may not cause noticeable symptoms, so attending regular eye exams is important.

Here are the answers to some common questions about cataracts and vision loss.

What happens to cataracts without treatment?

Without treatment, cataracts can lead to progressively worsening vision and negatively affect a person’s overall quality of life.

Can doctors reverse blindness from cataracts?

Doctors can typically reverse vision loss due to cataracts through cataract surgery. Cataract surgery is a highly effective procedure that involves removing the cataract and replacing it with an IOL.

This surgical intervention can significantly improve a person’s vision and, in many cases, restore it to a level where they can see clearly again.

What percentage of people with cataracts go blind?

According to the International Agency for the Prevention of Blindness, over 17 million people globally were blind due to cataracts in 2020. However, several factors can affect the risk of blindness from cataracts.

Cataracts do not always cause blindness, and people can prevent complete vision loss if they have access to prompt treatment.

Cataracts cause a clouding of the eye’s lens, which can gradually worsen. If someone with cataracts does not seek treatment, they may experience vision impairment, which could result in blindness.

However, healthcare professionals can use surgical methods to treat cataracts, replacing the clouded lens with a clear artificial lens.

Early diagnosis and timely intervention through cataract surgery are crucial for preserving and restoring clear vision.