Understanding the Different Causes and Classifications of Cataracts
Cataracts are one of the most common causes of gradual vision loss, particularly as people get older. They occur when the natural lens of the eye becomes cloudy, preventing light from passing clearly through to the retina. As the lens becomes more opaque, images appear blurred or dim, and tasks such as reading, driving or recognising faces can become difficult.
Although cataracts most often develop with age, they are not exclusive to older adults. Factors such as eye injury, diabetes, certain medications or even congenital conditions can contribute to their formation. Understanding the different types of cataracts can help explain why symptoms vary and why timely assessment is important for maintaining clear vision.
The Main Types of Cataracts
Cataracts are generally classified according to their location within the lens or their underlying cause. Each type has distinctive characteristics and patterns of vision change.
Understanding the different types of cataracts helps explain how they affect vision clarity and colour perception over time.
Nuclear Sclerotic Cataract
A nuclear sclerotic cataract is the most common age-related form, typically developing in the central zone (nucleus) of the lens. Over time, the lens fibres harden and take on a yellow or brown tint. This can cause gradual blurring of distance vision, duller colour perception and more difficulty driving at night due to glare from headlights.
Some people notice their close-up vision briefly improves in the early stages, a phenomenon sometimes called “second sight.” However, as the cataract progresses, overall vision continues to decline, and glasses can no longer correct the blur.
Cortical Cataract
A cortical cataract forms in the outer layer of the lens, known as the cortex. It appears as white or wedge-shaped streaks that extend toward the centre. These changes scatter light entering the eye, often causing glare, halos and sensitivity to bright light.
This type of cataract can affect both near and distance vision, depending on how much of the lens is involved. It is often linked with diabetes or prolonged exposure to sunlight, but can also develop without a clear cause.
Posterior Subcapsular Cataract
A posterior subcapsular cataract develops near the back surface of the lens capsule, close to where light focuses on the retina. Because of its location, it tends to interfere most with reading and other near-vision activities.
People with this type often notice significant glare or halos around lights, especially when driving at night. It usually progresses faster than other forms and is more common in people who take steroid medications or have certain metabolic conditions.
Congenital Cataract
A congenital cataract is present at birth or develops during early childhood. It may result from genetic factors, developmental abnormalities or maternal infections during pregnancy. Early detection is critical, as cataracts that obstruct vision in infants can disrupt normal visual development. In many cases, timely surgery or treatment allows the child’s visual system to develop correctly, giving them the best chance of good long-term sight.
Secondary Cataract
A secondary cataract can form as a complication of another health condition, such as diabetes, or as a side effect of long-term steroid use. It can also refer to a clouding of the thin capsule that holds the lens in place after cataract surgery, known as posterior capsule opacification.
While the latter is sometimes called a “secondary cataract,” it is not a new cataract forming but rather a natural reaction of the lens capsule after surgery. This can be easily treated using a quick laser procedure to restore clarity.
Traumatic Cataract
A traumatic cataract develops following an injury to the eye, such as a blunt force impact, penetrating wound or exposure to intense heat or radiation. The cataract may form soon after the trauma or take years to become noticeable.
The severity and speed of development depend on the nature of the injury and how deeply it affected the lens. In most cases, surgical treatment can remove the damaged lens and restore clear vision once the eye has healed.
Comprehensive eye assessments at Ashford Advanced Eye Care help detect different cataract types and plan effective treatment.
How Different Cataracts Affect Vision
Although all cataracts cause cloudy or blurred vision, the exact symptoms depend on the type of cataract and where it sits within the lens.
- Nuclear cataracts often reduce clarity for distance tasks and give colours a brownish or yellow tint.
- Cortical cataracts create glare, halos and difficulty seeing in bright sunlight.
- Posterior subcapsular cataracts cause issues with near vision and sensitivity to oncoming headlights.
- Congenital, traumatic and secondary cataracts can affect vision at any age and vary greatly in severity.
Regardless of the type, cataracts can significantly impact quality of life. Reading, driving and recognising faces can become increasingly difficult. Fortunately, cataract surgery is a safe, highly effective way to restore clear vision once the clouding starts to interfere with daily activities.
When to Book an Eye Assessment
If you experience cloudy or blurred vision, glare from lights or colours that seem less vibrant, it may be time for an eye assessment. Identifying the type of cataract early allows for appropriate monitoring and timely treatment.
At Ashford Advanced Eye Care, every cataract assessment is performed by a highly qualified ophthalmologist using state-of-the-art diagnostic technology. Patients receive a personalised care plan and, when needed, access to advanced cataract surgery options.
To arrange an appointment or referral, contact the clinic directly on (08) 8293 2700 or submit an enquiry through the online booking form. New patients and referrals are always welcome.
FAQs
What are the different types of cataracts?
The main types of cataracts include nuclear sclerotic, cortical, posterior subcapsular, congenital, secondary and traumatic cataracts. Each develops in a different part of the lens and causes distinct visual changes.
Which type of cataract is most common?
The nuclear sclerotic cataract is the most common type, typically forming as part of the natural ageing process. It usually affects distance vision first and progresses slowly over time.
Can you have more than one type of cataract at the same time?
Yes, it is possible to develop mixed cataracts where more than one area of the lens is affected. In these cases, symptoms may overlap and progress at different rates.
How do cataracts affect your vision?
Cataracts scatter light entering the eye, causing blurred or cloudy vision, glare and loss of contrast. The impact depends on the cataract’s type, location and density.
Can cataracts form after eye surgery?
Yes, a condition known as posterior capsule opacification can occur after cataract surgery, which may feel like a new cataract. It can be corrected quickly with a painless laser procedure.
Are cataracts only caused by ageing?
While ageing is the leading cause, cataracts can also result from eye trauma, medical conditions such as diabetes, or long-term steroid use. Some people are born with congenital cataracts due to genetic factors.
How are cataracts diagnosed?
An ophthalmologist can diagnose cataracts through a detailed eye examination that includes vision testing and slit-lamp assessment. This helps identify the cataract type and its effect on visual clarity.
When should I see a specialist for cataracts?
You should book an eye assessment if you notice blurred vision, glare or faded colours that affect your daily activities. Early evaluation ensures the right timing for treatment and the best outcome for your sight.
