It hides because of where it starts. The damage begins at the edges of vision, and the brain papers over the gaps for years. By the time you notice a chunk of the world missing, the optic-nerve fibres that mapped it are dead and don't grow back. So the hard part is detection: treatment is cheap and works, but it only protects what you still have.

Treatment is about as settled as medicine gets. Lowering eye pressure slows glaucomatous vision loss by roughly half, about 10% less progression risk per 1 mmHg dropped ¹. In people with high pressure but healthy nerves, treating it halved the five-year odds of developing glaucoma ². But nothing reverses damage already done.

Some people should start young. Prevalence runs about half a percent in your 40s and climbs toward seven percent by your late 70s ³. It's roughly four times as common in adults of African descent, with onset about a decade earlier ⁴. Glaucoma in the family, a thin cornea, or strong nearsightedness each raise your odds too ². If two fit you, use the earlier schedule below.

Book a comprehensive dilated eye exam. It runs $50 to $200, is often covered by insurance, and takes under an hour. Ask for the optic-nerve look and an OCT scan, not just a pressure reading.

What the exam buys you. If you're clear, you leave with a clean baseline that makes the next scan easier to read. If something's caught, a daily drop or a one-time in-office laser holds it roughly in place for the decades of vision you'd otherwise lose. Skip it long enough and the loss runs one way: you stop driving at night, then stop driving, then miss a grandchild crossing the kitchen.