Glaucoma is a group of eye disorders associated with optic nerve damage. It may lead to permanent blindness if not well managed. It is asymptomatic in the early stages and can easily be missed. The effect is so gradual that you may not notice a change in vision until the condition is at an advanced stage and that is why a significant number of glaucoma patients present in an advanced stage of the glaucoma and so there is a danger of losing the vision.
Patients with advanced glaucoma has near total cupping of the optic nerve with or without severe visual field loss.
Glaucoma symptoms may include blurred vision, vomiting and nausea, halos around lights, headache, eye redness etc.
Tunnel vision as illustrated the above image is the symptom of advanced glaucoma.
The patient may complain of visual functional impairment like unable to see the parts of words bumping into things more often, transient visual loss, visual hallucination.