The most common form of glaucoma, open angle glaucoma,
can strike without warning, pain or symptoms.Thus, it is
called
"the sneak, thief of sight".
A second form of glaucoma, closed angle, is far less common.
Its onset
is sudden with severe eye pain, eye redness and a change in
vision. Closed angle
glaucoma requires immediate medical attention.
http://www.glaucoma.org
American
Optometric Association
National
Eye Institute