What are Cataracts? Causes, symptoms and treatment

Types of cataracts

Cataracts develop in different parts of the lens, which is why symptoms vary from person to person. Understanding the type of cataract helps explain why glare, colour changes, or difficulty reading may appear earlier in some individuals than others.

Nuclear cataracts develop in the centre of the lens, often causing gradual changes in clarity and altering the way colours appear. This sometimes gives vision a yellow or brown tint as the lens gradually changes colour. As this develops, you may notice increasing short-sightedness.

Cortical cataracts form around the outer edge of the lens. It often creates spoke-like streaks that extend inward. These streaks scatter light in a way that can produce glare and reduce contrast. This happens especially in low light, making night driving a much more difficult activity.

Posterior subcapsular cataracts develop at the back of the lens. Clouding here often makes reading more difficult and can produce intense glare in bright light. This type tends to progress faster than others, and it's more common in people with diabetes or those who take steroid medication.

Congenital cataracts are present from birth or develop during early childhood. These are less common and are usually identified during routine eye checks. Symptoms include involuntary eye movements, clouded or misty vision or a squint. Early treatment is important for developing vision, with congenital cataracts often removed early if they are negatively impacting visual clarity.

With clear differences in the way each cataract affects the lens, it's easy to see why the experiences people describe can vary so much.

Can cataracts be prevented?

Cataracts can't be prevented outright, but some habits are consistently linked to a lower risk of the lens becoming cloudy more quickly. Many of these habits also support wider eye health, so even if a cataract has started to form, they're still worth adopting.

Because long-term sunlight exposure is a recognised risk factor across multiple clinical sources, a good place to start is to protect your eyes from UV light. Wearing good-quality sunglasses that provide strong UV protection can help limit this exposure and reduce the strain placed on the lens fibres.

Lifestyle choices also play a role. Smoking appears in every major-factor list - meaning that stopping this habit is likely to have the most direct positive impact.

Restricting your alcohol intake to moderate levels is recommended due to the link between excessive drinking and a higher likelihood of cataract development.

For people living with diabetes, careful blood sugar management is important for protecting the lens. Raised blood sugar is a recognised contributor to faster cataract progression, which means staying on top of treatment and regular monitoring can make a significant difference.

Diet is another area where small changes help over the long term. There is value in maintaining a nutrient-rich diet, particularly one that includes fruits and vegetables containing natural antioxidants. These nutrients support the health of the lens and may help slow the progression of clouding, even though supplements themselves haven't been proven to prevent cataracts.

The last habit to change is the easiest one to implement: make sure you go for regular eye examinations - especially if you're older than 60. With several types of cataracts developing gradually, early clouding can go unnoticed for years. Routine checks create an opportunity to spot subtle changes, monitor progression, and discuss the right timing for treatment long before vision becomes significantly affected.

Whilst these steps won't prevent a cataract from forming entirely, they give you the best chance of preserving the health of the lens, and this is a key contributor to maintaining clearer vision for as long as possible.

How cataracts are diagnosed

Many people feel nervous before their first eye appointment, often worrying about discomfort or being given difficult news. In reality, a cataract assessment is usually calm, routine and painless. Your specialist will take time to talk through your symptoms, check how clearly you can see and examine your eyes using a bright light. In some cases, dilating drops are used to allow a clearer view of the lens and the back of the eye.

The purpose is straightforward and reassuring. It is simple to understand how much the cataract is affecting your day-to-day vision and to check whether anything else needs attention.

An appointment with a specialist covers the following steps:

• Personal history - A cataract diagnosis usually starts with a discussion about the visual changes someone has noticed. You'll be asked about your symptoms, how they impact your daily life and about your general health, medications and whether there is any family history of eye issues.
• Visual acuity test - This test checks how clearly each eye can see at different distances. This assessment helps determine whether the blur or mistiness comes from the lens or is caused by another part of the eye.
• Slit-lamp examination - This is used to view the eye under magnification. With this tool, the clinician can see the lens directly and identify cloudy patches, their location and their density. Even early cataracts that are invisible in a mirror become visible during this step.
• Dilation exam - Pupil dilation is often used to widen the view of the lens and the retina. This helps determine how much of the lens is affected, and vitally allows the consultant to check that there are no other issues contributing to reduced vision. The drops used to dilate the pupil may blur near vision for a few hours, but this wears off over the course of a day.

Together, these tests confirm whether a cataract is present, what type of cataract and how advanced it is, and crucially, how much of the visual change described it is responsible for.

Cataract treatment options

Surgery is the only way to treat cataracts once they start to affect your day-to-day sight, and it is one of the most routine procedures carried out in modern healthcare. Even so, it is completely natural to feel a little anxious when the word "surgery" is mentioned, especially when it involves your eyes.

Many people find it helps to think about the process in simple, reassuring steps. You arrive at the clinic, your eye is gently numbed with drops or a small injection, and the procedure itself is short. The cloudy lens is removed and replaced with a clear artificial one, and you go home the same day with eye drops and a protective shield. There is no need for an overnight stay, and you are awake but comfortable throughout.

Knowing what to expect and being reassured about what will not happen often helps the whole experience feel calmer and far less daunting.

When to seek help

When clouding in the lens begins to interfere with everyday activities, it's time to consider a more permanent solution. Glasses or brighter lighting can help for a time, but they can't reverse the changes inside the lens. Removing the cloudy lens and replacing it with a clear artificial one is the only effective and lasting way to treat a cataract.

An assessment is recommended if blur or mistiness becomes persistent or if glare makes activities feel less safe. Increasing difficulty with night driving, repeated struggles with reading despite new glasses, or problems recognising faces can also suggest that the cataract is progressing. Frequent changes in glasses prescriptions are another clue.

Sudden vision changes require prompt attention because cataracts do not normally cause rapid deterioration. Symptoms such as a sudden drop in vision, significant redness, pain or new flashes of light should be assessed immediately.

Speaking with an eye professional can clarify what is happening and when the best time is to have cataract surgery. Some people benefit from simple monitoring. Others find it helpful to explore surgical options earlier so they can plan with confidence.

Choices before surgery

One thing that often surprises people is that cataract surgery is not just about removing the cloudy lens. It also involves choosing a new artificial lens that will shape how you see afterwards. Some lenses focus on clear distance vision, others aim to reduce the need for glasses at more than one distance, and some are designed to correct astigmatism.

This is a very personal decision, based on how you use your vision every day, whether that is reading, driving, using screens or a mix of all three. There is no single "best" lens for everyone. Taking time to understand your options and what they mean for your lifestyle can make a real difference, which is why we explore this in more detail in our guide to Cataract lens options: which is best for you?

What is cataract surgery like?

Cataract surgery is a straightforward procedure, usually with the eye numbed using a local anaesthetic. If a patient is feeling anxious, a mild sedative might be given.

Initially, a very small opening is created near the edge of the cornea.

The surgeon then removes the cloudy lens through this using a process called phacoemulsification. This is an ultrasonic method in which a fine probe softens and breaks the cataract into tiny fragments that are then gently lifted out.

Once the cataract has been removed, a clear artificial lens is placed inside the eye. The new lens unfolds gently into the natural lens capsule and sits where the original lens used to be.

There are various lens options available, including monofocal lenses for one distance, multifocal lenses that support both near and far vision, toric lenses for correcting astigmatism, and extended-depth-of-focus lenses designed to provide a more natural range of vision.

The surgical part of cataract treatment usually only takes around 15 to 30 minutes. Stitches usually aren't required, as the small incision created at the beginning is designed to seal on its own.

Most people go home the same day as the surgery, and start noticing the first signs of clearer vision within a day or two. These early changes are normal, as the eye continues to heal and settle over the following weeks as part of the wider cataract recovery process.

Risks, safety, and outcomes

It is natural to focus on risk when thinking about cataract surgery - but it is a safe and straightforward day procedure, and serious complications are rare. The OCL Vision team has an outstanding track record for safety and patient outcomes, supported by detailed pre-operative planning and careful monitoring throughout recovery. Most people begin to notice clearer vision within the first 24 to 48 hours, and the eye continues to settle over the following weeks with the help of clear aftercare guidance.

Although any operation carries a small chance of problems such as infection, inflammation or temporary visual disturbances, these are rare and usually improve with fast, targeted treatment. Serious complications that permanently affect sight are uncommon, and your surgeon will talk you through your individual situation, including cataract risk and recovery, based on the health of your eye and your general health.

A later clouding of the lens capsule, known as posterior capsular opacification, can sometimes develop but is treatable with a short laser procedure if needed. OCL Vision provides access to support around the clock, so any concerns during the healing process can be addressed quickly and reassuringly.

Recovery is often easier than people expect. Many notice brighter, sharper vision within days, with colours appearing clearer. Eye drops are used for a few weeks, and some short-term precautions help the eye heal safely, with vision continuing to settle gradually.

Frequently asked questions

If you find yourself building up a long list of questions about cataract treatment, you are not alone.

If you or a loved one is thinking about cataract treatment, it's natural to think of plenty of questions. People often wonder about driving afterwards, what this means for their glasses and prescription, or what recovery really looks like. These are very common concerns, even if everyone phrases them slightly differently.

We've put together the most common questions we're asked below to help put your mind at ease. If you think of something not covered here, or if you would rather talk it through with an experienced specialist, the OCL Vision team is always happy to help and can discuss your situation in more detail.

Do cataracts affect both eyes?

Cataracts can develop in one eye or both, and it is very common for adults to experience changes in each eye over time. They often appear in both eyes eventually, but not always at the same pace. One eye may become cloudy earlier or progress more quickly, and this can create a noticeable imbalance between the two.

Because each lens can change at a different rate, people sometimes find that vision is clearer on one side, or that activities such as reading, driving or judging distances feel uneven. This difference is normal and doesn't mean something is wrong - it's due to the differing rates at which cataracts may develop.

If someone has symptoms in only one eye, it is still important to have both eyes examined. Early clouding is often subtle, and it can be picked up long before it causes noticeable vision problems. Regular checks help track any differences between the eyes and guide the right timing for treatment when it is needed.

What does vision look like with cataracts?

Your vision may feel slightly foggy or coated, similar to looking through a lightly clouded window when a cataract is forming. Lights can produce halos, contrast becomes harder to judge, and colours may appear washed out. In more developed stages, vision may appear filtered through a cloudy layer due to protein clumps, which scatter and block light from reaching the retina.

Are cataracts painful?

Cataracts do not typically cause discomfort. They affect the inner lens rather than the surface of the eye, so the eye usually feels normal even as vision becomes less clear. This is another reason that it can be easy to ignore subtle changes in your vision when they are forming.

What happens if cataracts are left untreated?

Cataracts usually progress slowly over a period of years. More light is blocked, and vision becomes gradually more blurred or misty as the clouded area in the lens grows.

If left untreated, the result is a gradual degradation of clear sight that can't be repaired or reversed by any means other than surgery.

Will I go blind if I have cataracts?

If cataracts are left untreated for a long time, they can cause severe vision loss and, in some cases, blindness.

With modern eye care, cataracts do not usually lead to blindness. They are a physical problem with a well-established and effective treatment. While surgery may be delayed for practical or personal reasons, permanent vision loss from cataracts is now largely preventable.

What is the best age for cataract surgery?

There is no fixed "best age" for cataract surgery, but cataracts are most common in people over 65, and many adults only need surgery when the clouding of the lens begins to interfere with daily activities.

The timing of cataract surgery is based on how much the cataract affects your vision and day-to-day tasks, not your age. Surgery is recommended when glasses no longer help and your ability to read, drive, or manage bright or dim light is reduced.

How quickly does sight deteriorate with cataracts?

The exact speed at which sight deteriorates due to cataracts varies from person to person. As cataracts progress gradually, the decline in clarity becomes more significant as a larger part of the lens is affected. Age-related cataracts are more likely to cause sight deterioration over the years, whereas cataracts caused by other factors, like trauma, are more likely to progress faster.

Can cataracts come back after surgery?

The cataract itself cannot come back. During surgery, the cloudy natural lens is removed entirely, so it can't regrow.

Sometimes months or years later, it is possible that the thin membrane holding the artificial lens in place can become cloudy. As it can feel the same, this is sometimes confused with the cataract "coming back," even though it is a different issue.

This is called posterior capsular opacification and is explained in more detail in our Can cataracts return after surgery? guide. It is treated with a quick, painless laser procedure, and vision usually clears again soon afterwards.

Can cataracts cause dizziness and headaches?

Cataracts do not directly cause dizziness or headaches, but the changes they create in vision can contribute to both. As the lens becomes cloudy, light is scattered, and vision is less clear, which can lead to glare, reduced contrast and eye strain.

For some people, this extra effort to focus can trigger headaches or a feeling of pressure around the eyes. If cataracts affect one eye more than the other, the imbalance in visual input can also cause a sense of unsteadiness or lightheadedness, particularly in busy settings.

Does reading in dim light cause cataracts?

No, reading in dim light doesn't cause cataracts. It can lead to temporary eye strain or headaches because your eyes have to work harder, but it does not damage the eye or cause the lens to become cloudy.

Can perfect eye care guarantee I won't get cataracts?

Even with excellent eye care and healthy habits, cataracts cannot be completely prevented. Looking after your eyes can reduce risk and may delay when cataracts develop, but age and genetics still play a major role, so there is no way to guarantee you will never get cataracts.

Are you concerned about changes in your vision?

Changes to sight can feel unsettling, especially when they appear gradually. Many people adapt without realising how much clarity they have lost. If glare, mistiness or difficulty with daily tasks has become more noticeable, an eye examination can help clarify what is happening. A professional assessment can confirm whether a cataract is present, how significant it is and what steps might be helpful.