了解白内障形成和发展的各个阶段

Cataracts develop in four stages: early, immature, mature and hypermature. As the eye’s natural lens becomes progressively cloudier, vision moves from mildly blurred to severely impaired. Knowing which stage a cataract has reached helps you understand your symptoms and when treatment may be needed.

A cataract can affect anyone, but it becomes far more common with age, and factors such as diabetes, smoking, long-term steroid use and prolonged sun exposure can speed its development.

A cataract can affect anyone, but certain factors make some individuals more susceptible. In most cases, this condition is prevalent among those over 60. Factors such as diabetes, smoking, and prolonged sun exposure can increase the risk of cataract formation and development.

The impact of cataracts goes beyond blurred vision; it can affect your everyday activities and quality of life. When left unmanaged, cataracts can develop into different stages that affect how you see and function. As such, it’s essential to be aware of the different signs of each cataract stage so you can get the care and treatment needed to manage the condition.

What Are the 4 Stages of Cataract Development?

Eye specialists commonly describe cataract progression in four stages, based on how cloudy the lens has become and how much vision is affected. You may also hear these described as levels or grades, for example a level 2 or grade 2 cataract, which correspond to the same progression.

Stage 1: Early Cataract

In the early stage, sometimes called an incipient cataract, the lens is still largely clear, but it is beginning to lose flexibility and small areas of clouding may start to form. Many people notice nothing at all, and early cataracts are often picked up during a routine eye examination.

Common signs at stage 1:

• Slightly blurred or hazy vision
• Increasing difficulty shifting focus between near and far
• Mild glare or light sensitivity, especially at night
• More frequent eye strain or tiredness

What to do: no treatment is usually needed at this stage. Updating your spectacle prescription, using brighter light for reading and wearing UV-protective sunglasses can manage the symptoms. From this point on, regular eye checks are recommended so any progression is picked up early.

Stage 2: Immature Cataract

At the immature stage, often described as a level 2 or grade 2 cataract, proteins within the lens have begun to clump together and the clouding becomes visible on examination. This is typically the point at which symptoms start to interfere with daily life.

Common signs at stage 2:

• Noticeably blurred or dimmer vision
• Difficulty driving at night due to glare and halos around lights
• Colours appearing faded or yellowed
• Trouble with reading and other close work
• Frequent changes to your spectacle prescription

What to do: many people manage well at this stage with updated prescriptions and anti-glare lenses, but this is a sensible time to see an eye specialist. Monitoring how quickly the cataract is progressing helps with planning treatment before vision deteriorates further.

Stage 3: Mature Cataract

A mature cataract means the lens has become significantly or completely opaque. The clouding may now be visible to others as a whitish or amber discolouration of the lens, and vision is severely affected.

Common signs at stage 3:

• Severely blurred or misty vision that glasses can no longer correct
• Marked difficulty with night driving, reading and recognising faces
• Strong glare sensitivity and pronounced halos
• A visible white, grey or brownish tint in the pupil

What to do: at this stage, visual aids rarely provide meaningful improvement, and cataract surgery is usually recommended. Most people who reach the mature stage find daily activities noticeably restricted, and this is the most common trigger for surgical treatment.

Stage 4: Hypermature Cataract

A hypermature cataract is the most advanced stage. The lens has hardened and shrunk, and the proteins inside it begin to break down. Vision loss is severe, and the cataract itself becomes technically more difficult to remove.

What can happen at stage 4:

• Severe visual impairment, in some cases limited to perceiving light and movement
• Inflammation within the eye caused by leaking lens proteins
• Raised pressure inside the eye, which can damage the optic nerve and lead to glaucoma

If a hypermature cataract triggers raised eye pressure, prompt assessment is needed and 青光眼治疗 may be required alongside cataract removal. Reaching this stage is avoidable, as cataracts are routinely treated well before they become hypermature.

Cataract Stages at a Glance

How Are Cataract Stages Diagnosed and Graded?

The stage of a cataract cannot be reliably judged from symptoms alone. During a cataract screening, your pupils are dilated and the lens is examined under a slit lamp, a microscope that lets the specialist see exactly where the clouding sits and how dense it has become. Your visual clarity and eye pressure are checked at the same visit.

Specialists often record cataracts using clinical grading scales, which score the density and location of the clouding. This is why you may see a term such as grade 2 nuclear cataract in an eye report. The grade reflects severity and broadly corresponds to the stages described above, and it allows change to be measured accurately between visits so that treatment can be timed appropriately.

Which Cataract Stage Needs Surgery?

There is no rule that a cataract must reach a particular stage, or become ripe, before it can be removed. Modern techniques can treat a cataract at any stage, and waiting too long can make the procedure more complex, particularly once a cataract becomes hypermature.

In practice, 白内障手术 is usually considered when:

• Vision interferes with daily activities such as reading, driving or recognising faces
• Glasses or contact lenses no longer provide adequate correction
• The cataract is affecting the management of another eye condition
• The cataract has reached the mature stage, where progression will only continue

Most people have surgery somewhere between the late immature and mature stages. If you are unsure which stage your cataract has reached, an assessment with an eye specialist can give you a clear picture and help you plan the timing that suits you.

Why Consider Cataract Surgery?

Undergoing surgery when advised by your cataract eye specialist can help prevent your condition from becoming so severe that it may affect your ability to see and function in your daily life. Moreover, timely surgical intervention ensures better outcomes, faster recovery, and a higher likelihood of preserving overall eye health. With the restoration of clear vision, you can resume activities that you may have gradually withdrawn due to visual impairment.

These days, as healthcare progresses, cataract surgeries have evolved to become a more minimally invasive procedure. Therefore, you can expect minimal discomfort during and after surgery.