What are cataracts?
A cataract is a gradual clouding of the eye's natural lens. Many people first notice it as increasing blur, more glare in bright sunlight or from oncoming headlights, reduced contrast, or a feeling that vision is no longer as crisp as it once was.
Cataracts usually develop slowly. In the early stages, symptoms may be mild, but over time they can begin to interfere with reading, driving, work, and overall visual comfort.
Common symptoms of cataracts
Symptoms can develop gradually and may affect one eye more than the other.
- blurred or "hazy" vision that slowly worsens
- increased glare or halos around lights, especially at night
- colours appearing less vivid or more muted
- difficulty with reading or fine detail
- frequent changes in glasses prescription
- reduced contrast or clarity in everyday settings
Not every change in vision is caused by cataracts, which is why a proper eye examination matters. A comprehensive eye exam can clarify this.
Why cataracts develop
Cataracts are most commonly age-related, but they may also be associated with diabetes, previous eye injury, prolonged steroid exposure, or prior eye surgery. The pace of change varies from person to person.
A careful examination helps determine whether lens changes are truly the main cause of symptoms or whether another part of the eye also needs attention.
How cataracts are evaluated
Cataract evaluation is based on both examination findings and real-world visual function. The aim is not simply to identify changes in the lens, but to determine whether those changes explain the patient's symptoms.
Evaluation typically includes:
- visual acuity testing
- refraction when appropriate
- slit-lamp examination to assess lens clarity
- dilated retinal examination when indicated
- imaging-based measurements of the eye to support treatment planning when needed
- assessment of overall ocular health, visual needs, and lifestyle factors
In some cases, additional imaging or measurements may be performed to better understand visual quality and plan treatment.
This approach ensures that treatment decisions are based on the full clinical picture, not just the presence of a cataract.
When treatment becomes appropriate
Treatment becomes appropriate when cataracts begin to meaningfully affect day-to-day activities such as driving, reading, work, or general visual confidence. The decision is individual and depends on both symptoms and examination findings.
The goal is to identify the right time for treatment rather than waiting until vision becomes severely limited. For broader symptom guidance, see .
How cataract surgery works
Cataract surgery involves removing the clouded natural lens through a small incision and replacing it with a clear artificial intraocular lens (IOL). The procedure is performed under local anaesthesia, typically takes 15-30 minutes, and most patients return home the same day.
Modern cataract surgery is one of the safest and most effective operations in medicine, with a high success rate for improving vision.
Surgical planning
Precise measurements of the eye are taken before surgery to select the most appropriate lens power. The artificial lens is chosen based on these measurements and your visual needs, with the aim of providing the best possible outcome for distance vision.
Dr Stavrou discusses the surgical plan with each patient so you understand what to expect before, during, and after the procedure.
What to expect before and after surgery
Before surgery, a detailed assessment confirms that cataract surgery is appropriate and that the eye is healthy enough for the procedure. Pre-operative measurements guide lens selection.
After surgery, most patients notice improved vision within a few days. Follow-up visits monitor healing, check eye pressure, and assess visual recovery. Eye drops are prescribed for a short period to support healing.
Recovery and results
Most patients can return to normal activities within a few days of cataract surgery. Vision continues to improve over the first few weeks as the eye heals. Driving is usually possible once vision meets the required standard, which your surgeon will advise on.
Some patients experience mild dryness or light sensitivity in the early recovery period, which typically resolves. Updated glasses may be prescribed once the eye has fully settled.
Secondary cataract (posterior capsule opacification)
Some patients develop gradual clouding of the membrane behind the implanted lens months or years after cataract surgery. This is often called a "secondary cataract," although it is not the original cataract returning.
When it affects vision, it is treated with a quick, painless YAG laser capsulotomy in the office. Any reduction in clarity after prior cataract surgery should be properly assessed.