Cataract is a common eye condition caused when the lens in your eye becomes cloudy or opaque. The lens is a clear structure of the eye that refracts light to focus it precisely on the retina. When cataracts form, they block light from passing through the lens, leading to blurry vision. This condition is prevalent among older adults, but it can affect anyone. This condition affects millions of people worldwide, especially as they age. According to the World Health Organization , cataracts are responsible for 51% of world blindness.
Types of Cataracts
Cataracts can be categorised by where they form in the natural lens in the eye and by their causes.
Types of cataracts based on the location in the lens of the eye
1. Nuclear Cataracts
These types of cataracts develop in the central zone of the lens, known as the nucleus. They usually occur as a result of ageing and can cause the lens to harden and turn yellow, which can lead to difficulty in distinguishing colours, increased glare sensitivity and cause vision changes.
2. Cortical Cataracts
It occurs in the lens cortex (the outer edge of the lens). They begin as white cloudy spots that grow from the edge to the center of the lens. This type of cataract often causes glare and depth-perception issues.
3. Posterior Subcapsular Cataracts
These form at the back of the lens and tend to progress faster than other types of cataracts. Posterior subcapsular cataracts can cause reading difficulties and glare or halos around lights.
Types of Cataracts Based on their Causes
1. Age-related Cataracts
These are the most common types of cataracts and occur as we grow older. They are linked to changes in the lens structure when the protein components start to break down, form together in a cluster causing the lens to become cloudy.
2. Congenital Cataracts
Some babies are born with cataracts due to genetic defects, infections or diseases passed bythe mother during pregnancy. This type of cataract can affect a child’s vision development and will need prompt treatment. Children can also develop cataracts, known as childhood cataracts.
3. Secondary Cataracts
These cataracts develop as a result of cataract surgery when some remaining cataract cells start to form on the lens capsule, a thin membrane surrounding the lens and supporting its shape. Certain risk factors include diabetes, uveitis or retinitis pigmentosa.
4. Traumatic Cataracts
These cataracts result from ocular trauma caused by either blunt force or a penetrating eye injury, affecting the lens fibers. They may develop immediately after the injury or appear years later.
Symptoms of Cataracts
Cataracts usually develop slowly and symptoms may not be noticeable at first. As they develop, the following symptoms may appear:
1. Blurry Vision
The most common symptom is blurry vision. You might feel like you are looking through a foggy or cloudy window.
2. Difficulty seeing at night
Cataract can make it difficult to see at night. You may notice halos around lights or glare that makes driving at night both difficult and hazardous.
3. Sensitivity to light
Increased sensitivity to light and glare is another symptom. Exposure to bright lights may feel uncomfortable or cause squinting.
4. Fading colours
Colours may appear less vibrant or faded, making it challenging to distinguish between similar shades.
5. Frequent prescription changes
As cataracts worsen, your glasses or contact lens prescription may change more frequently to accommodate vision loss.
What Causes Cataracts?
The following factors can lead to the development of cataracts:
1. Medical conditions
Certain medical conditions can increase the risk of cataracts. Diabetes, for instance, is a significant risk factor. People with diabetes are more likely to develop cataracts and they may progress faster. Hypertension is also an associated risk factor of cataracts forming in the eye.
2. Lifestyle factors
Lifestyle choices, such as smoking and excessive alcohol consumption, can also lead to cataracts. Smoking generally doubles the risk of developing age-related cataracts.
3. Over-exposure to harmful sun rays
Prolonged exposure to sunlight without adequate eye protection can increase the risk of cataracts. UV radiation from the sun can damage the lens of the eye.
4. Genetic factors
Genetics play a role in cataract development. If there has been family history of cataracts, such to say your parents or siblings, you may be more likely to develop the condition.
Treatment for Cataracts
Cataract treatment depends on the severity of the condition.
Surgical Options
Surgery is the most effective treatment for cataracts. The procedure involves removing the clouded lens and replacing it with a clear artificial lens called intraocular lens (IOL). Lenses can be removed in two ways:
1. Small incision cataract surgery (phacoemulsification): This is the most common type of cataract surgery. A small incision is made in the cornea and an ultrasound is used to break the cloudy lens into tiny pieces, which are then gently removed through the incision.
2. Extracapsular cataract surgery: This method involves a larger incision to remove more dense cataracts by extracting the hard centre of the lens in one piece. The remaining lens material is then removed using suction.
Cataract surgery is generally safe and successful, with a recovery period that allows most patients to return to normal activities within a few weeks.
Please note: If cataracts affect both eyes, surgery is usually carried out on one eye at a time. Optometrists will treat each eye separately for safe recovery.
When to See an Optometrist?
If you notice any symptoms of cataract affecting your vision, it’s essential to consult an optometrist at the earliest. Regular eye examinations can help detect cataracts early and allow for timely intervention.
Frequently Asked questions
1. How do cataracts form?
Cataracts form when proteins in the eye’s natural lens break down and clump together, causing the lens to become cloudy over time.
2. What are the early signs of cataracts?
Early signs of cataracts include blurred or cloudy vision, increased sensitivity to light and difficulty seeing clearly at night.
3. How to stop cataracts from getting worse?
Cataracts cannot be reversed. However, wearing sunglasses, managing health conditions and early detection can help reduce the progression.
4. Do cataracts always need surgery?
No. Surgery for cataracts is usually recommended only when it begins to significantly affect daily activities like reading and driving.
5. How fast do cataracts progress?
Cataracts typically develop slowly over several years, but progression can vary depending on the individual and underlying health factors.
Having graduated from City and Islington College in 2016, Krina Halai is a certified Dispensing Optician working with Feel Good Contacts. With 13 years of experience in the optical field, she has worked in multiple practices, including Boots and Specsavers, performed paediatric dispensing, supervised and trained future optical professionals and triaged patients for numerous spectacle fittings, repairs and adjustments. She has also taken an online course on myopia control and helped many children prevent their myopia from progressing.
