Cataracts: Symptoms, Causes and Treatment

Overview  |  Signs  |  Symptoms  |  Diagnosis  |  Types |  Risk Factors |  Treatments

A cataract is one of the most common eye disorders. It affects millions of people around the world.

What is a cataract?

As people age, the lens of the eye changes. Cataracts occur when proteins in the lens clump together. The light scatters when passing through the lens because it can no longer focus properly on the retina.

As the condition progresses, your vision may decline if it is not treated. 

Watch this video to learn more about what a cataract is:

What are the first signs of cataracts?

The first signs of cataracts are cloudy, dim, or blurred vision. It might seem as if you are looking through frosted glass. 

You may find it increasingly difficult to read or have reduced night vision. But during the earliest stages, you might not notice any differences.

Eye specialists (ophthalmologists) can often identify the issue long before patients experience symptoms themselves. For this reason, regular eye tests are important, especially in people aged 40 and over.

Cataract symptoms

With age-related cataracts, most people’s symptoms worsen over time. These include:

  • Cloudy, dim, or blurred vision
  • Halo effects around lights 
  • Reduced night vision
  • Difficulty reading
  • Colours appear faded or yellow
  • Finding bright light and glare uncomfortable
  • Prolonged double vision in one eye or both
  • Often need to change glasses or contact lens prescription
  • Needing a brighter light for reading and other activities
  • Your eyes appear darker; more common with advanced cataracts


It’s common for both eyes to be affected. But, they may not develop simultaneously or to the same extent.


What does a cataract look like?

You might see an opaque or almost-white spot anywhere over your eye. It may not be visible in the early stages or if it’s at the back of your eye. 

In the later stages, it may look like a milky or amber film covering most of your eye. We call this a mature cataract. At this stage, your cataract will be visible in the mirror and to other people.

Diagnosing cataracts

Regular eye examinations mean we can look for early signs of cataracts, which will help us monitor and treat your condition earlier.

We can do a series of tests to look for signs of and diagnose cataracts, including:

  • A visual acuity test – an eye chart with letters that decrease in size
  • Slit lamp exam – allowing us to view the structure of your eye
  • Retinal exam – this involves using eye drops to dilate your pupils
  • Applanation tonometry – to measure fluid pressure in your eye


During testing, we will need to look at your eye health as well as your vision quality. We will also discuss your medical and relevant family history to determine your risk of cataracts.


Cataract self-testing

You cannot accurately test yourself for cataracts. But, you can decide whether you should see a professional by looking at the symptoms of cataracts. Reading the risk factors for cataracts may also help your decision. You can find these later down this page.

Though, ultimately, if you experience a change in vision or new symptoms, we recommend booking an eye test.

Types of cataract

There are four common types. The differences are in their appearance and how they progress. 

Congenital cataracts may be present from birth or develop in childhood. They are usually hereditary but may occur from infection or trauma during a mother’s pregnancy. We also call these early-onset cataracts.

Cortical cataracts begin at the outer edges of the lens. They develop as pale streaks or patches. Slowly moving toward the centre, these streaks obstruct light from passing through the lens.

Nuclear cataracts appear in the centre of the lens, causing near-sightedness in the initial stages. With time, your lens turns yellow or even brown which affects colour perception.

Posterior subcapsular cataracts are small, opaque areas that form at the back of the lens, directly in the path of light. It commonly causes glare around lights at night, reading vision problems and light sensitivity.

Risk factors for cataracts

You may be at higher risk of cataracts if:

  • You’ve had previous eye surgery
  • A family history of cataracts
  • Spending a lot of time in the sun
  • Eye injury, inflammation, or eye diseases
  • Regular radiation exposure e.g. X-rays, cancer treatments
  • Certain medical issues, such as diabetes and high blood pressure
  • Taking medicines like corticosteroids or statins for a long time
  • Lifestyle factors, such as smoking, excessive alcohol consumption and obesity


To an extent, you can manage and prevent cataracts by making certain lifestyle changes. Such as quitting smoking, drinking less, wearing sunglasses in the sun, and eating a healthy diet.

Cataract treatments

In the early stages, you can get new prescription glasses or contact lenses to assist your vision. 

If your eyesight is more seriously impaired, ophthalmologists recommend surgery, such as lens replacement surgery. 


A cataract can only be fully treated with surgery. This involves replacing your cataractous lens with a synthetic lens implant (IOL) which stays in your eyes for life. It won’t be visible to you or anyone around you.

Cataract surgery options include:


With private cataract surgery, you can normally opt for either an ‘accommodating’ or ‘multifocal’ type of lens. These enable you to change focus between distant and near objects.

You’re more likely to experience complications if you have existing health problems or other eye conditions. These include macular degeneration or glaucoma.

Sometimes, surgery is not enough. If you have underlying illnesses, you may want to consider treatments for those first.

Book an appointment

If you notice any changes in your vision, book an appointment with one of our eye specialists to get tested for cataracts. We will provide a full assessment of your eyes and vision.

We also offer a second opinion service. If you have sought help already but believe a problem with your eye health has been missed, we can help.


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0330 128 1616

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The Care Quality Commission (CQC)

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