Content verified by
What are cataracts?
Cataracts develop over time and occur when the lens (the clear part of your eye that lets in light) becomes clouded. At first, you might not even notice you have a cataract, but over time it will continue to grow larger, and eventually cause changes to your vision.
Cataracts can form in one or both of your eyes and can occur at different times. Despite the serious impact they can have on your vision, cataracts can be removed with a simple surgery which also prevents them from returning in the future.
Cataract surgery is a minimally invasive treatment, and is available at our leading ophthalmology centre at St Thomas’ Hospital.
Ophthalmology specialists
At Guy’s at St Thomas’ Specialist Care, our ophthalmology services offer:
- short-notice appointments
- fast and accurate diagnosis
- quick access to treatment
Who is at risk of developing cataracts?
Some people may be more at risk of developing cataracts than others. Some of the main risk factors include:
- smoking
- diabetes
- excessive alcohol consumption
- a family history of cataracts
- previous eye injuries or surgeries
- spending a lot of time in the sun without protective eyewear
- taking corticosteroids to help with conditions like arthritis
It’s not possible to prevent or slow the growth of cataracts but there are things you can do to lower your risk. Having regular eye check-ups is vital to catch any problems as early as possible.
Protecting your eye health is another important factor. Giving up smoking and protecting your eyes from ultraviolet (UV) rays can reduce your overall risk of cataracts.
If you’re at risk of developing cataracts and want to discuss your concern with a specialist, get in touch.
Human eye with a normal lens and an eye with cataracts.
Cataract symptoms
Generally, symptoms of cataracts are so mild when they first appear that you won’t even notice them, but they will worsen over time.
Some of the main visual symptoms associated with cataracts include:
- cloudy or blurry vision
- colours looking dull
- a yellowing of colours
- difficulty seeing at night
- sunlight feeling too bright
- seeing a halo shape around lights
- seeing double (this usually occurs when cataracts are smaller)
- your glasses or contact lens prescription keeps needing to be changed
- needing a brighter than usual light for activities like reading
If you’re displaying symptoms of cataracts, get in touch and book an appointment to consider your treatment options with a specialist.
What causes cataracts?
Cataracts are most often related to ageing. As you get older, the lens in your eye becomes thicker and less clear. This happens when the proteins and fibres within your lens break down and clump together to form a cataract.
As the cataract develops, it gradually blocks light from passing through your lens and prevents clear images from being created by your retina (the light-sensitive tissue at the back of your eye).
Cataracts and glaucoma
Cataracts and glaucoma are not usually directly related, but it is possible that one condition can lead to the other.
A cataract may become large enough to block the eye’s drainage channels, leading to fluid build-up and increased pressure that causes glaucoma. There is also the chance that cataracts could form after you have glaucoma surgery.
When to see a doctor for cataracts
If you are experiencing any changes or problems with your vision, always speak with one of our consultant ophthalmologists. While it could be cataracts, there may also be another underlying eye condition in need of treatment.
Diagnosing cataracts
Cataracts can be diagnosed with a standard eye test and are often detected by opticians at routine eye tests. At an eye test, your optician will test your vision at various distances and check your overall eye health with a slit lamp examination (which shows them the inside of your eye) and an eye pressure check. If they detect a cataract in one or both of your eyes, they will refer you for treatment to remove it.
Sometimes, cataracts are detected at an eye test before you even begin to experience visual symptoms. In these cases, you may not need treatment immediately, but may choose to opt for it further down the line once your vision starts to become affected.
To arrange an assessment with an ophthalmology specialist, get in touch to discuss your symptoms and the most appropriate next steps.
Cataract treatment
Cataract surgery is the only type of treatment that is proven to be effective for cataracts. Our expert ophthalmologists offer different types of cataract surgeries. Your consultant will determine the best type for you based on the severity of your condition.
During cataract surgery, the consultant will make small incisions in the side of the eye and use ultrasound probes, in a technique called phacoemulsification, to break up the cataract. These are not lasers, as is commonly believed. The consultant then removes the cataract and old lens, before replacing it with the artificial lens. The operation usually takes about half an hour per eye.
The consultant will discuss with you the difference types of artificial lens implant available. Various upgrade options are available, particularly to reduce the need for glasses and contact lenses after the procedure. The option to upgrade your type of lens is not available with NHS cataract surgery, however private patients who visit our ophthalmology department at St Thomas’ Hospital for their cataract surgery have the option to choose a vision-correcting lens when booking their cataract surgery.
Book an appointment with Guy’s and St Thomas’ Specialist Care
At Guy’s and St Thomas’ Specialist Care, we offer a range of cataract treatments to support and protect your vision. Our ophthalmology team consists of world-class consultants who will provide you with unparalleled service and care.
If you are struggling with cataracts or problems with your vision, book a consultation with our specialists. Our dedicated team will help you book an appointment that’s convenient for you and get your vision back on the right track.
Reviewed regularly to reflect clinical best practice
Last reviewed: 28 March 2025
Locations
Our private ophthalmology services are offered at the following locations:
Discover our ophthalmology specialists
