Symptoms of Glaucoma

Most glaucoma gives no warning in the early stages. This is why it is called the "sneak thief of sight". By the time vision changes are noticed, much of the nerve damage may have happened, and it cannot be reversed.

Open-angle glaucoma (the common type)

• No pain and no redness
• Slow loss of side (peripheral) vision, often unnoticed because the other eye compensates
• Tunnel-like vision in advanced disease

Emergency: acute angle-closure glaucoma

The drainage angle suddenly closes, and pressure shoots up. Symptoms include:

• Severe eye pain and headache
• Blurred vision and halos around lights
• Red eye
• Nausea and vomiting
• A hard, painful eye

This is a medical emergency. Go to an eye hospital or casualty the same day, or call 112 or 102. Delay can cause permanent blindness within hours to days.

Other signs that need an eye check

• Patchy blind spots
• Frequent changes in glasses
• Trouble adjusting to dim light
• Eye pain on and off with halos in the evening

Children

Watery, enlarged or cloudy eyes, light sensitivity and rubbing in a baby may point to congenital glaucoma. See a paediatric eye doctor urgently.

Key point

Because early glaucoma is silent, regular eye checks after age 40, or earlier with a family history, matter more than waiting for symptoms.

Before your eye appointment

Carry your old reports, glasses and a list of all drops, tablets and supplements you use. Note any family history of glaucoma, diabetes or steroid use, and write down when symptoms occur. This helps your eye doctor choose the right tests and plan, and spot changes early.