Cataracts

What it is

The lens sits behind the iris and focuses light. Proteins in the lens clump with age (and faster with diabetes, steroids, UV exposure and smoking), scattering light and reducing sharp vision. Most cataracts develop slowly over years in both eyes, though one eye may be ahead.

Symptoms

Changes are gradual and painless.

• Blurry, misty or cloudy vision
• Glare and halos around lights, especially night driving
• Faded or yellowed colours
• Frequent glasses prescription changes
• Double vision in one eye
• Needing brighter light to read

When surgery is considered

There is no rush purely because a cataract is visible on examination. Surgery is offered when vision affects daily life — reading, driving, work, hobbies or confidence. Your surgeon discusses timing if one eye is much worse, or if cataract blocks view of the retina in diabetes.

What surgery involves

Phacoemulsification breaks up the cloudy lens through a small opening and an intraocular lens (IOL) is implanted. Most people have local anaesthetic drops or injection and go home the same day. Read the preparing for cataract surgery guide for pre-op steps.

Lens implant choices

Standard monofocal IOLs give clear distance vision with reading glasses likely needed. Toric IOLs correct astigmatism. Multifocal or extended-depth-of-focus lenses reduce glasses dependence for some people but may increase glare or halos — discuss pros and cons with your surgeon.

When to seek urgent care

Cataracts do not cause sudden vision loss. Seek emergency assessment for sudden blur, flashes, floaters, eye pain or a curtain over vision — those suggest retinal detachment, glaucoma or other problems.