Cataracts are very common. In fact, they’re the main cause of impaired vision worldwide. In England and Wales, it’s estimated that around 2.5 million people aged 65 or older have some degree of visual impairment caused by cataracts.
Types of cataracts
There are three types of cataracts:
- Nuclear cataracts affect the centre of the lens and can make it difficult to distinguish colours
- Cortical cataracts affect the outer edge of the lens
- Posterior subcapsular cataracts form at the back of the lens. They interfere especially with reading and cause haloes to form around lights. This type of cataract tends to progress faster than the other types1.
Cataracts usually develop slowly over many years, so you may not notice symptoms at first. They often develop in both eyes, although each eye may be affected differently.
Cataracts are not painful and don’t make your eyes red or irritated. You’ll usually have blurred, cloudy or misty vision, or you may have small spots or patches where your vision is less clear.
What are the early signs of cataracts?
In most people, cataracts develop with age. As you grow older, the lens in the eye naturally becomes thicker, less transparent, and less flexible. Tissues in the lens can begin to break down and form clumps of protein that cloud small areas of the lens. Light cannot pass through these cloudy areas, which is why you may notice your vision becomes clouded or bleary.1 As the cataract continues to grow, the cloudiness becomes more noticeable and involves larger parts of the lens.
Besides cloudy, dim, or blurred vision, there can be other symptoms associated with a cataract. These include difficulty with night vision, haloes around lights, sensitivity to glare, fading of colours, and double vision on one side. People with cataracts may find they require brighter lights to read. Also, frequent changes in your glasses or contact lens prescription can indicate cataracts.1
Cloudy vision: how to tell if it's a sign of cataracts
You might have cloudy vision if objects in the distance seem ‘milky’, like you’re looking at them through a frosted window. This can affect your day-to-day life, making it difficult to do some normal activities. However, there are many causes of cloudy vision, including eye conditions like myopia, astigmatism and cataracts. But how do you know if this is the cause of your cloudy vision?
What causes cloudy vision?
Cloudy vision can take a toll on your lifestyle, often making it difficult to read, drive, or see faces clearly. Several eye conditions can cause this, including:2
- Myopia (short-sightedness): objects at a distance appear blurry
- Astigmatism: both near and far objects appear distorted and blurry
- Presbyopia: age-related change in the ability to focus on near objects
- Cataracts: cloudy vision due to changes in the lens of the eye affecting vision at all distances
There are also other less common causes of cloudy vision, including corneal abrasions (where the cornea becomes scratched), dry eyes, or scarring of the cornea (the clear part in front of the eye). On top of this, other causes can include optic neuritis, macular degeneration, diabetic retinopathy, infections and inflammation. If you’re experiencing a sudden deterioration in vision, you should seek immediate medical attention.
Why do cataracts cause cloudy vision?
The lens of the eye works like a camera to focus light on the retina and form images, adjusting to allow us to see objects at varying distances. Cataracts are made up of clumps of protein which cloud the lens – it’s a bit like cooking an egg white where the transparency gradually gives way to milky cloudiness. Usually, both eyes are affected, but vision may be better in one eye than the other.3
Cataracts mainly occur in older people, often developing as part of the natural ageing process. In fact, in the UK, cataracts account for more than one-third of the cases of vision impairment in people over the age of 75.4
Many cases of early-stage cataracts do not affect the eyesight substantially and you’d usually be unaware of any vision problems, which is why regular eye tests are so important to detect any changes. A common first symptom of early cataracts, however, is that night vision may not seem as good as it once was. As the cataract grows, more of the lens gets clouded and there may be more noticeable symptoms.
What causes cataracts?
Cataracts occur when cloudy patches develop in the clear lens inside your eye, stopping light from reaching the back of the eye, and causing blurred or misty vision. In most people, cataracts simply develop as they age, with most cases developing after the age of 65. But there are other factors that can increase your risk of developing cataracts, including:
- A family history of cataracts
- Regularly drinking excessive alcohol
- Lifelong exposure of your eyes to UV light
- A poor diet lacking in vitamins
- Taking steroid medication over a long time
- Certain health conditions, such as diabetes
Cataracts and myopia
Short-sightedness, or myopia, is a very common eye condition that affects an estimated 1.4 billion people worldwide. In people who are myopic, light entering the eye does not focus onto the retina, making close objects appear sharp and well-defined, but objects at a distance appear blurred. As such, nearsightedness may not affect someone’s ability to read a book or look at a computer screen, but it makes it difficult to watch a film, read a whiteboard in a classroom, or see clearly when driving.5,6 While these symptoms can be easily managed with prescription glasses or contact lenses, undiagnosed nearsightedness can sometimes cause eye strain and headaches, or squints in children.
For most people, treating myopia is as simple as wearing prescription glasses or contact lenses to correct their vision. Research has found a link between people with high myopia and a greater risk of developing other eye conditions, including cataracts.7 In particular, one study found that cataracts are more likely in people who began using distance glasses before the age of 20, as well as in people over the age of 55 who develop nearsightedness.7, 8 While the precise link between high myopia and cataracts is not completely clear, it’s believed that severely myopic eyes have reduced levels of protective antioxidants, which could make them more prone to developing cataracts.7 Below we’ve outlined a few steps that can help to minimise the risk of developing cataracts:9
- Quit smoking
- Drink alcohol in moderation
- Eat foods rich in antioxidants and vitamins, such as fruit and green leafy vegetables
- Protect your eyes from UV damage by wearing high-quality sunglasses
- If you are diabetic, keep your blood sugar under control
If you suspect that you may have cataracts, it’s best to make an appointment with a specialist. Regular eye exams make it possible to spot problems such as cataracts early on. For more information on cataracts, you can book an appointment with a Specsavers optometrist.
How are cataracts diagnosed?
Cataracts can usually be picked up during a normal eye test, which is why it’s important to have one regularly (once every two years or more frequently if your optometrist recommends it). During an eye exam, your optometrist will assess how well you can see at varying distances, as well as having a good look at your overall eye health. If they think you have cataracts, it’s likely that they will refer you to an eye specialist (ophthalmologist) who can confirm the diagnosis and plan your treatment.
What is the treatment for cataracts?
If your cataracts are mild, stronger glasses and brighter reading lights may be helpful for some time. However, most cataracts get worse over time (often many years) so it’s likely you will eventually need treatment. The only treatment that is proven to be effective for cataracts is surgery, which improves vision for most people.10 This will usually be recommended if your loss of vision is affecting your daily activities, such as driving or reading.
Cataract surgery is done under local anaesthetic, so you’ll be awake, but your ophthalmologist will make sure you don’t feel the area around your eye, and you can be sedated if you are particularly anxious. It’s a very common and successful procedure and involves taking out the cloudy lens and replacing it with a clear, artificial one. This artificial lens cannot cloud over in the same way, and so cataracts do not grow back after surgery.
There are two types of cataract surgery: small incision cataract surgery (phacoemulsification) and extracapsular cataract extraction. These surgeries are usually done on an outpatient basis, so you shouldn’t need to stay at the hospital overnight, and it usually takes less than an hour to perform.
During this type of cataract surgery, the surgeon inserts a tiny ultrasound probe into the eye through a small incision. The probe helps soften and break up the cloudy lens, which is then removed by suction. Once the surgeon has removed the cataract, they will insert an artificial lens (called an intraocular lens) which will allow light to pass through to your retina, restoring your vision.
Extracapsular cataract extraction
In extracapsular cataract extraction (ECCE), the surgeon will make a slightly larger incision to remove the clouded lens. As before, once the clouded lens has been removed, a new, transparent, intraocular lens is positioned in the same place from where the natural one was removed.
The new lens is made of plastic, silicone, or acrylic and remains in the eye permanently. It cannot be seen or felt. It improves vision by focusing light clearly on the retina.11
Cataract surgery and macular degeneration
Cataracts can be easily treated with surgery, but there are some conflicting reports about the relationship between cataract surgery and age-related macular degeneration (AMD). The traditional view is that cataract surgery could increase the risk of AMD progressing. However, more recent studies have shown that patients with mild to moderate macular degeneration and moderately severe cataract can benefit from cataract surgery14.
Whether cataract surgery should be performed on an individual with AMD is a complicated decision. Your ophthalmologist will first need to find out which of the conditions is the primary cause of your vision worsening. In some people with advanced AMD, the retina may be damaged to such a degree that cataract surgery will not noticeably improve vision. In other people, cataract surgery can significantly improve vision and quality of life14.
Large multi-centre studies have shown there is no increased risk of progression to the advanced (wet) form of AMD in patients who undergo cataract surgery.15,16 Moreover, nutrients such as vitamin C, vitamin E, zinc, lutein, and zeaxanthin have been found to substantially reduce the risk of AMD progressing to advanced stages17.
Complications from cataract surgeries are rare. In patients with AMD, the clinical approach may simply need to be altered and some special precautions taken. There is usually no need to stop treatment for macular degeneration: anti-VEGF injections for AMD can continue in people who have, or who have not undergone cataract surgery18. These are injections that reduce the growth of new blood vessels beneath the macula.
Book an appointment
If you ever have any concerns about your eye health, book an appointment as soon as you can. Adults should get their eyes examined every two years, or more frequently if recommended by your optometrist, to identify any eye problems before they begin to affect vision.
1. Mayo Clinic. (no date). Cataracts. [Online]. Available at: https://www.mayoclinic.org/diseases-conditions/cataracts/symptoms-causes/syc-20353790 [Accessed 2 September 2019].
2. National Eye Institute. (no date). Facts About Cataract. [Online]. Available at: https://nei.nih.gov/health/cataract/cataract_facts [Accessed 31 August 2019].
3. Harvard Health Publishing. (published July 2010). By the way, doctor: What can I do to prevent cataracts. [Online]. Available at: https://www.health.harvard.edu/newsletter_article/what-can-i-do-to-prevent-cataracts [Accessed 31 August 2019].
4. The Royal College of Ophthalmologists. (no date). The Way Forward. [Online]. Available at: https://www.rcophth.ac.uk/wp-content/uploads/2015/10/RCOphth-The-Way-Forward-Cataract-300117.pdf [Accessed 31 August 2019].
5. American Optometric Association. (no date). Myopia (near-sightedness). [Online]. Available at: https://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/myopia [Accessed 31 August 2019].
6. National Eye Institute. (no date). Facts About Myopia. [Online]. Available at: https://nei.nih.gov/health/errors/myopia [Accessed 31 August 2019].
7. Younan C, Mitchell P, Cumming RG, Rochtchina E, Wang JJ. Myopia and Incident Cataract and Cataract Surgery: The Blue Mountains Eye Study. Investigative Ophthalmology & Visual Science. December 2002, Vol.43, 3625-3632. [Online]. Available at: https://iovs.arvojournals.org/article.aspx?articleid=2162247 [Accessed 31 August 2019].
8. Brown NA, Hill AR. Cataract: the relation between myopia and cataract morphology. Br J Ophthalmol. 1987;71(6):405–414. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1041188/ [Accessed 29 August 2019].
9. WebMD. (no date). How can I prevent cataracts? [Online]. Available at: https://www.webmd.com/eye-health/cataracts/how-can-i-prevent-cataracts#1 [Accessed 31 August 2019].
10. National Eye Institute. (no date). Facts About Age-Related Macular Degeneration. [Online]. Available at: https://nei.nih.gov/health/maculardegen/armd_facts [Accessed 2 September 2019].
11. American Academy of Ophthalmology. (no date). What is Macular Degeneration? [Online]. Available at: https://www.aao.org/eye-health/diseases/amd-macular-degeneration [Accessed 2 September 2019].
12. Mayo Clinic. (no date). Cataracts Diagnosis and Treatment. [Online]. Available at: https://www.mayoclinic.org/diseases-conditions/cataracts/diagnosis-treatment/drc-20353795 [Accessed 2 September 2019].
13. American Optometric Association. (no date). Cataract Surgery. [Online]. Available at: https://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/cataract/cataract-surgery [Accessed 2 September 2019].
14. Wong, TY. Cataract surgery in patients with cataract and age related macular degeneration: do the benefits outweigh the risks? British Journal of Ophthalmology 2000;84:1337–1341 [Online]. Available at: https://bjo.bmj.com/content/bjophthalmol/84/12/1337.full.pdf [Accessed 2 September 2019].
15. Armbrecht AM, Findlay C, Kaushal S, Aspinall P, Hill AR, Dhillon B. Is cataract surgery justified in patients with age related macular degeneration? A visual function and quality of life assessment. British Journal of Ophthalmology Volume 84, Issue 12. [Online]. Available at: https://bjo.bmj.com/content/84/12/1343 [Accessed 2 September 2019].
16. Starr MR, Mahr MA, Barkmeier AJ, Iezzi R, Smith WM, Bakri SJ. Outcomes of cataract surgery in patients with exudative age-related macular degeneration and macular fluid. American Journal of Ophthalmology 2018 Aug;192:91-97. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pubmed/29802819 [Accessed 2 September 2019].
17. National Eye Institute. (no date). Age Related Eye Disease Study Results. [Online]. Available at: https://nei.nih.gov/research/clinical-trials/age-related-eye-disease-study-areds [Accessed 2 September 2019].
18. STEVEN S. SARAF, CHRISTINA L. RYU, AND MICHAEL D. OBER. (2015) The Effects of Cataract Surgery on Patients With Wet Macular Degeneration. Available at: https://www.ophed.net/system/files/2015/09/Article2_Cataract_AMD.pdf [Accessed 10 February 2022].19. Harvard Health Publishing. (published July 2010). By the way, doctor: What can I do to prevent cataracts. [Online]. Available at: https://www.health.harvard.edu/newsletter_article/what-can-i-do-to-prevent-cataracts [Accessed 31 August 2019].