What is a cataract assessment?
A cataract is a clouding of the natural lens inside your eye. It is an extremely common age-related change — most people will develop some degree of cataract by the time they reach their 70s. In the early stages, cataracts may cause no noticeable symptoms, but as they develop, you may experience blurred or misty vision, increased glare from headlights or bright lights, colours appearing faded or washed out, and difficulty seeing in low light. A cataract assessment determines the extent of your cataract, how much it is affecting your vision, and whether the time is right for a referral for surgery.
During the assessment, your optometrist will examine the lens of your eye using a slit lamp microscope, often after dilating your pupils with drops to get a clearer view. They will also measure your visual acuity to establish how much your vision is being affected and discuss the impact on your daily life — your ability to read, drive, watch television, and carry out your normal activities. The NHS guidelines for cataract surgery referral are based on the impact on your quality of life, not simply on the clinical appearance of the cataract.
Cataract surgery is one of the most commonly performed operations in the UK, with around 450,000 procedures carried out each year on the NHS. It is a highly successful day-case procedure that typically takes 15–30 minutes under local anaesthetic. Your optometrist will refer you to a hospital eye department or an accredited independent sector treatment centre when your cataracts are significantly affecting your daily life. In the meantime, updating your glasses prescription can often improve your vision while you are waiting.
Who needs a cataract assessment?
- Anyone experiencing gradually worsening blurred or cloudy vision
- People noticing increased glare or haloes around lights, especially when driving at night
- Those over 60 who have been told they are developing cataracts
- Anyone whose glasses prescription changes are no longer improving their vision
- People finding it harder to see in dim lighting or finding colours look faded
- Those with a history of eye injuries, steroid use, or diabetes (which can accelerate cataract development)
What to expect during a cataract assessment
- 1Your optometrist will review your symptoms and how your vision is affecting your daily activities
- 2Visual acuity is tested to measure how clearly you can see at distance and near
- 3Drops may be used to dilate your pupils for a better view of the lens
- 4The lens of each eye is examined under the slit lamp to assess the type and severity of the cataract
- 5Your optometrist will discuss whether referral for surgery is appropriate based on the impact on your quality of life
- 6If referral is needed, the process and what to expect from cataract surgery will be explained
How much does it cost?
Free as part of an NHS-funded eye test. Private cataract assessments typically £30–£50. Cataract surgery is free on the NHS
How often should you have this test?
As needed, based on symptoms. Once cataracts are detected, monitoring every 6–12 months is typical until referral is appropriate