- Medically Reviewed by Mr Mfazo Hove Consultant Ophthalmologist
- Author: Chris Dunnington
- Published: October 2, 2025
- Last Updated: October 7, 2025
Glaucoma has rightly earned the nickname “the silent thief of sight”. This stealthy group of eye conditions can cause irreversible vision loss, sometimes before patients know anything is amiss. Early intervention is key and recognising signs – however subtle – can mean the difference between healthy vision and permanent damage.
Here are seven warning signs to watch for, as recognised by the expert team at Blue Fin Vision® Eye Clinic.
Infographic: 7 Early Warning Signs of Glaucoma
Gradual Loss of Peripheral Vision
Peripheral vision vanishes quietly.
Many people notice a subtle narrowing of their visual field, often missing objects just outside their direct line of sight. Routine comprehensive eye exams detect this early, long before noticeable decline. Monitoring side vision, especially if you’re over 40 or have a family history, is vital – Harley Street’s top specialists use advanced visual field testing to reveal subtle changes.
Tip: Request regular perimetry testing for optimal glaucoma screening at your London clinic.
Tunnel Vision in Advanced Cases
Central vision remains, but the world shrinks.
When glaucoma progresses, patients may experience tunnel vision, where only the centre of their vision remains, and the sides are lost. This is a late warning sign, highlighting why earlier screening is crucial. Leading clinics like Blue Fin Vision® use optical coherence tomography (OCT) for precise monitoring and early treatment.
Stat: Over 700,000 UK people have glaucoma, with half undiagnosed – early tests matter.
Difficulty Adapting to Low Light
Eyes struggle in dim environments.
Adjusting from bright to dark spaces becomes challenging. This issue, often blamed on ageing, can indicate early optic nerve compromise. Modern clinics, such as those on Harley Street, recommend asking about low-light vision during your exam as an added safeguard.
Insight: Difficulty transitioning between light levels is not just a nuisance – report it to your eye doctor.
Slight Changes in Colour Perception
Colours may lose vibrancy, especially blues and yellows.
Glaucoma can cause subtle shifts in colour discrimination, and patients may notice that colours appear faded or less distinct. This clue is often picked up during professional colour vision testing. Blue Fin Vision® uses advanced screening to detect these nuanced changes in your vision.
Practical tip: If hues seem duller or odd, don’t dismiss it – schedule a check-up.
Increased Sensitivity to Light and Glare
Bright lights become a bother.
Some experience uncomfortable glare or light sensitivity, signalling possible optic nerve stress from glaucoma. This symptom can emerge before other signs and should be mentioned during every eye screening. Clinics with top technology, like Blue Fin Vision®, can differentiate glaucoma from other light-sensitive conditions for personalised care.
Tip: Noticing headlight glare worsening on night drives – timely diagnostic scans detected early optic nerve damage.
Eye Pain, Redness, or Discomfort
Sudden or persistent eye pain is a red flag.
Acute glaucoma attacks cause severe pain, redness, and sometimes headache or nausea. Most early glaucoma stays painless, but any ocular discomfort deserves prompt review. Harley Street’s rapid-access clinics deliver urgent care with proven outcomes.
Tip: Never ignore new eye pain – make it a priority, even if it passes quickly.
Blurred Vision or Seeing Halos
Vision blurs or halos appear around lights.
Blurring and seeing rings around lights, especially in dim settings, may precede more serious symptoms. While blurry vision can result from other causes, in the context of glaucoma risk it warrants immediate attention. The best London clinics use precise OCT imaging to determine the true cause, guiding tailored treatments.
Insight: Halos around lights are especially common in angle-closure glaucoma – seek input from a glaucoma specialist.
Recap
- Gradual loss of peripheral vision: silent and subtle.
- Tunnel vision: advanced but critical.
- Challenges with low-light adjustment.
- Colour perception changes.
- Light sensitivity and glare issues.
- Pain, redness, or discomfort in the eye.
- Blurred vision and halos.
For more details, see Blue Fin Vision®’s in-depth glaucoma guides or ask our specialist team about advanced screening options for peace of mind.
Protect Your Vision with Blue Fin Vision®
Glaucoma rarely shouts; it whispers. Spotting early signs means you can take charge of your sight before it’s lost. The expert ophthalmologists at Blue Fin Vision® deliver comprehensive testing using the world’s best technology in London, Harley Street, Essex, and Hertfordshire. Trust your vision to proven top specialists, guided by Spears 2025 Top Recommended distinction.
Which sign was new to you? Share this list and help others protect their sight – download our Glaucoma Early Detection Guide or book your comprehensive eye exam today. Entrust your precious vision to Blue Fin Vision®, the definitive leader in glaucoma care.
Your eyesight is priceless – choose the clinic where excellence is guaranteed.
