Glaucoma Vision Simulator

What glaucoma can look like over time

Glaucoma slowly affects your side (peripheral) vision first, while your central vision stays sharp until late. Because the brain fills in the missing areas, it is easy to miss for years — which is why regular eye-pressure and optic-nerve checks matter. Step through the stages below to see how it can progress.

Overview

Glaucoma is one of the leading causes of irreversible blindness worldwide. It usually develops when fluid pressure inside the eye damages the optic nerve, the cable that carries images from the eye to the brain. The most common form (primary open-angle glaucoma) is slow and painless: it quietly removes side vision first, and because the brain fills in the missing areas, many people do not notice anything is wrong until a large amount of vision is already gone. That is why glaucoma is often called the “silent thief of sight” — and why routine eye exams that check eye pressure and the optic nerve are the best protection.

Symptoms of glaucoma

• Gradual loss of peripheral (side) vision, usually in both eyes — the earliest and most common sign
• Patchy blind or blurred spots in side or central vision that are easy to miss for years
• “Tunnel vision” in advanced disease, as the clear area narrows toward the centre
• Trouble seeing in low light or adjusting to dim rooms
• Acute angle-closure glaucoma is different and sudden: severe eye pain, headache, nausea or vomiting, halos around lights and rapidly blurred vision — a medical emergency

What causes glaucoma

• Raised intraocular pressure (IOP) when the eye’s fluid (aqueous humour) cannot drain efficiently
• Open-angle glaucoma: the drainage angle stays open but the internal filter (trabecular meshwork) drains too slowly over years
• Angle-closure glaucoma: the iris blocks the drainage angle, raising pressure quickly (acute) or gradually (chronic)
• Normal-tension glaucoma: optic-nerve damage occurs even though eye pressure measures in the normal range
• Secondary glaucoma from injury, inflammation, advanced cataract, certain medications (e.g. long-term steroids) or other eye conditions

Glaucoma risk factors

• Age over 60 (and over 40 for some groups)
• A parent, brother or sister with glaucoma
• African, Hispanic/Latino or Asian ancestry (higher risk and earlier onset for certain types)
• High intraocular pressure
• Thin corneas, or high near-sightedness or far-sightedness
• Diabetes, high blood pressure, or long-term steroid use
• A previous eye injury or eye surgery

Prevention & early detection

• Glaucoma cannot be prevented, but vision loss usually can be — if it is caught early
• Have a comprehensive dilated eye exam on schedule: typically every 1–2 years from age 40, or sooner if you are higher-risk
• Know your family history and tell your eye doctor
• If you are diagnosed, use prescribed eye drops exactly as directed — consistent use is the single biggest factor in protecting vision
• Protect your eyes from injury and stay physically active; regular moderate exercise may slightly lower eye pressure

Treatment

Damage already done to the optic nerve cannot be reversed, but treatment can slow or stop further loss — so the vision you have can usually be protected. The goal is to lower eye pressure to a target that keeps the optic nerve safe, then monitor it for life. First-line treatment is usually daily pressure-lowering eye drops. Laser procedures (such as selective laser trabeculoplasty, or an iridotomy for narrow angles) are common next steps. When drops and laser are not enough, surgery — trabeculectomy, a drainage implant, or minimally invasive glaucoma surgery (MIGS) — can lower pressure further. Which option fits depends on the type and severity of glaucoma, so it is decided with your eye doctor.