Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. A major risk factor is increased pressure in the eye. The disorders can be roughly divided into two main categories:  open-angle  and  closed-angle  (or  angle closure ) glaucoma.laucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. A major risk factor is increased pressure in the eye. The disorders can be roughly divided into two main categories:  open-angle  and  closed-angle  (or  angle closure ) glaucoma.
Q: A geochemical cycle that cycles material by mantle convection, subduction, and seafloor spreading is A: A geochemical cycle that cycles material by mantle convection, subduction, and seafloor spreading is TECTONIC. Weegy: erosion. The rock cycle includes the formation, breakdown, and reformation of a rock as a result of sedimentary, igneous, and metamorphic processes.
The Plume Model. The idea is straightforward. A mantle plume is a large column of hot rock rising through the mantle. The heat from the plume causes rocks in the lower lithosphere to melt. The largest (and most persistent) mantle plumes are presumed to form where a large volume of mantle rock is heated at the core-mantle boundary, about 1,800 miles below the surface, although smaller plumes may originate elsewhere within the mantle.