A cataract clouds the eye’s natural lens. Learn what gradual changes can mean and how treatment decisions are made.
When vision becomes cloudy
A cataract develops when the normally clear lens inside the eye becomes cloudy. Light no longer passes through it as clearly, so everyday tasks may become harder. Cataracts can affect one or both eyes and may progress at different speeds. They do not spread between eyes. Cataract overview.
Symptoms and when to seek help
Common changes include hazy vision, faded colors, glare from headlights, halos around lights, difficulty reading and poorer night vision. A glasses prescription may need changing more often. These symptoms usually develop gradually. Similar symptoms can have other causes, so an examination matters. Symptoms.
Get emergency help: Sudden loss of vision or sudden severe eye pain needs immediate assessment at an eye emergency service or emergency department. Do not assume it is a cataract or wait for a routine appointment. Urgent vision symptoms.
Why cataracts develop
Aging is the most common reason. Changes in lens proteins gradually reduce its transparency. Diabetes, smoking, previous injury or eye surgery, and long-term steroid use can also increase risk. Some cataracts occur earlier in life. Mention prescribed medicines during your assessment; do not stop them on your own. Causes and risks.
What the examination involves
An eye examination checks how well you see and looks at the lens and the rest of the eye, often after drops widen the pupils. This helps establish whether a cataract explains the change in vision. Before surgery, the eye is measured to help choose the replacement lens. Examination and surgical preparation.
Treatment and daily life
Brighter task lighting, glare reduction and an updated glasses prescription may help while symptoms are mild. Surgery removes the cloudy lens and replaces it with an artificial lens. It is the only established way to remove a cataract. Timing usually depends on how much your vision affects the activities that matter to you. Treatment options.
Surgery often improves sight, but outcomes vary. Risks include infection, inflammation, retinal detachment and problems with the replacement lens. Glasses may still be needed afterward. Ask about your expected recovery, follow-up and any other eye condition that could limit improvement. Benefits, recovery and risks.
Cataracts illustrated
Questions to bring to your consultation
- How much of my vision change is caused by the cataract?
- What are the benefits and risks of surgery for my eyes?
- Which lens options suit my reading, work and night-driving needs?
- Will I need glasses, help at home or time away from work?
Frequently asked questions
Does every cataract need surgery immediately?
No. Mild cataracts can often be monitored while vision remains adequate for daily activities. Discuss any safety concerns, particularly glare or difficulty driving. Timing.
Can new glasses remove a cataract?
They may improve vision for a time, but they do not clear the cloudy lens. Glasses and cataracts.
Can vision become cloudy after surgery?
Yes. The membrane behind the replacement lens can become cloudy later. This needs assessment and is different from the original cataract returning. Later cloudiness.
Related reading: Glaucoma and macular degeneration.
This information is educational and cannot diagnose an eye condition or replace an individual assessment.
Sources and further reading
- National Eye Institute: Cataracts
- NHS: Cataracts in adults
- NHS: Cataract surgery
- NHS: Vision loss and urgent symptoms
General educational information prepared October 2026. Treatments described are general options; availability and suitability require an individual assessment.
